Identify the correct word from the given options, which means the following :
Fear of crowds
a) Ochlophobia
b) Hydrophobia
c) Xenophobia
d) Whoopee

Hint: An irrational fear of something that is unlikely to cause harm is known as a phobia. People with phobias actively avoid the phobic object or situation or endure it with intense fear or anxiety. Phobias are also a type of anxiety disorder.

Complete answer:
 In the given question, we have to find a word for a given phrase “fear of crowds”. Fear of crowds is when someone is afraid of being in a crowd. One may have an anxiety attack if he/she is in a crowd. When a person cannot stay amidst a crowd even for a bit or cannot even face the thought of being in a crowd leads to a phobia.
Now, let us examine all the given options and find out the correct answer :
Option ‘a’ is Ochlophobia. It is an extreme or irrational fear or dislike of crowds. They have a feeling that the crowd will somehow become mob-like or violent.
Option ‘b’ is Hydrophobia. It is an extreme fear of water, especially as a symptom of rabies in humans.
Option ‘c’ is Xenophobia. It is a dislike for or prejudices against people from other countries. For example The resurgence of racism and xenophobia.
Option ‘d’ is Whoopee. It is an informal noun, used in exclamatory sentences. It means to express wild excitement or joy.
As we have examined all the given options, we can easily find out the correct answer. Here, the word which best expresses the meaning of the given phrase “fear of crowd” is “ochlophobia”.
So, the correct answer is “Option a” , ochlophobia.

Note:
There are many different phobias that are generated from the object(which causes phobia) itself. Here, “ochlo” is a Greek word which means “crowd”.