Astrong, persistent, and unwarranted fear of some specific object or situation is referred to as

Phobia

Explanation:

Phobia is a psychological state of a person. Phobia is related to an extreme level of fear from a specific object, things, place animals, etc. Phobia is a mental or psychological disorder. Mostly females have to find this problem. Phobia can be of a different type. The people who have a phobia from different things are to avoid that situation or place to go there. It is also called a type of anxiety disorder.  

Phobia are of different type such as

a is the answer because it just is

answer; the sound of a train whistle makes a woman think of an old friend; //

the smell of grass makes a by feel that spring is the best; (apex);