In general, an organism will be more likely to develop phobias of
a. dangers faced during natural circumstances
b. unnatural modern inventions, like cars
c. easily understood forces and pressures
d. dangers encountered in dreams and visions

In general, an organism will be more likely to develop phobias of dangers faced during natural circumstances - a.

Say you encounter a dog who is going past you and the dog bites you. This is a very natural and powerfully negative stimulus which will then create possibly a phobia against dogs. 

The Correct Answer is A.

Explanation:

Phobia is a haunting and without reasonable fear of any particular matter, Situation, or activity that reflects few or no real risk but causes limitless fear.Doctors are still unaware of the real cause of many phobias. However, Many researchers has found that these phobia causes are related to family history, leading to the belief that genetic factors may play an important role in the origin of persistent and irrational fear.

Iwould put 'think' in the blank