Which bones protect the spinal cord?
A) Flat
B) Irregular
C) Long
D) None of the above

Hint:The spinal cord is a long and fragile tube like structure which is present at the end of the brainstem till the spine. It consists of nerves which help in carrying the messages between the brain and the body.

Complete answer:
Before we find the correct answer, let us find out more about the spinal cord. The spinal cord is protected by bones, disc, ligaments and muscles. The spinal cord is made up of 33 bones called vertebrae. The spinal cord is divided into 5 parts,
i) Cervical cord
ii) Thoracic cord
iii) Lumbar cord
iv) Sacrum cord
v) Coccyx cord

Option A: The function of flat bones is to protect internal organs such as the brain, heart and pelvic organs.hence it can not protect the spinal cord, therefore, this is the incorrect answer.
Option B: irregular bones are bones which vary in both shape and structure and thus they do not fit in any other category. They have a complex shape and function in protecting the internal organs. They are present in the vertebral column and help in protecting the spinal cord. Therefore, this is the correct answer.
Option C: The function of the long bones is to support the weight of the body and facilitate movement.hence long bones can not protect the spinal cord, therefore, this is the incorrect answer.
Optio D: As one of the options is correct, therefore this is the incorrect option.

Thus, the correct answer is option (B) Irregular.

Note:Based on structure and shape, bones can be of four types,
>Long bones - They are hard and dense and help by providing strength, mobility and structure. Example: Femur or thigh bone.
>Short bones - They are cube shaped which have equal horizontal and vertical dimensions. Examples: Wrist and ankle bones
>Flat bones - They have brod surface and their principal function is providing extensive protection. Examples: Cranium, sternum, etc.
>Irregular bones - They are irregularly shaped and have function in protection of internal organs. Examples: Facial bones, spinal cord bones.