What is the prefix of the underlined word in the sentence below:

The scientist was trying to find the smallest organism under the microscope.

a. micro

c. scope

b. mic

d. no prefix

I think the correct answer from the choices listed above is option A. The prefix used in the sentence would be micro-. A prefix is a word or letters being added or placed before another word. From the word microscope, scope is the root word and micro - is added to denote that the scope here is seen in a microscopic scale.