The use of “afraid of” words is requires use of continuous present tense next to it. In the above case, it can be seen the use of “going” when she has always trying to visit the doctor.
The other words such as “go” or “to go” can’t fit grammatically to form correct sentence in the above given sentence.
Thus, the options (d), (b) and (a) are incorrect.
The use of “afraid of” words is requires use of continuous present tense next to it. In the above case, it can be seen the use of “going” when she has always trying to visit the doctor.
Therefore, the correct option is – c. going.