The blood does not clot for a person suffering from-
A) Sickle cell anemia
B) Hemophilia
C) Thalassemia
D) Hypoxia

Hint: As we know that, Blood is an essential body fluid in humans and animals that has some major functions and roles. It delivers necessary nutrients and transports oxygen, metabolic products away from the cell and provides them with oxygen. Blood contains- RBC, WBC, plasma, platelets and water in different proportions. When a vein or artery is broken, platelets allow the blood to clot. Clotting means to stop the blood flowing out of the body.

Complete answer:
Option A Sickle cell anemia- sickle cell anemia is a genetic disease of red blood cells. Normally red blood cells are of discs shaped which help them to travel along the body, but in sickle disease RBCs are sickle shaped hence the disease is named after the shape. It is a rare condition; it is an autosomal recessive condition. A person to get sickle anemia needs two copies of genes from both parents if one parent is carrier or having traits then also the progeny is likely to get. Symptoms are- at a younger stage like \[4 - 6\]months old it would be visible such as excessive fatigue from anemia, bedwetting from kidney problems, jaundice, swelling in hands and feet, frequent infections, pain in chest arms and legs. Anemia is a shortage or lack of RBCs. People with sickle cells are easily broken. Normally RBC stays up to \[120\]days but in sickle cells hardly \[10 - 20\]days.
So, option A is not correct
Option B Hemophilia- it is a disorder in which blood doesn't clot normally. The clotting factors present in blood are not sufficient in the body. This happens due to a mutation or change in genes, that provide instructions for making clotting proteins in blood. These genes are located in the X chromosome. Symptoms- excessive bleeding causing external and internal injuries, deep cut bruises which takes more prolonged time to heal due to lack of clotting proteins. Treatment- consist of medications to improve clotting factors.
So, option B is correct
Option C Thalassemia- it is an inherited blood disorder having less amount of oxygen in blood. As we know that in blood hemoglobin carries oxygen and transports to different organs via blood, so the count of hemoglobin is less in this disorder. Symptoms include- fatigue, anemia, weakness, dark urine, abdominal swelling etc. Treatment depends on severity of the disease as if a person had mild thalassemia, it can be maintained by proper diet, vitamin infused medications, exercise but severe thalassemia requires blood transfusions to maintain the hemoglobin or RBC count.
So, option C is not correct
Option D Hypoxia- the insufficient amount or lack of proper amount of oxygen in blood or body is called hypoxia. Hypoxia can be caused by acute anemia or asthma or stress which lower the oxygen level in the body. Symptoms include- shortness of breath, it can vary from person to person, cough, slow heart rate, fast heart rate, sweating. Treatment- taking an inhaler, regular checkup of oxygen level in the body. Absence of oxygen in the body can affect the tissues organs and they may stop working in severe conditions.
So, option D is not correct

So the correct answer is option A.
Note:
Mostly blood disorders are genetic oriented diseases and it can occur to any person. Blood contains more RBC than WBC in the body. RBC are alive \[120\] days while WBC can live up to \[13 - 20\] days.