Select the option that is related to the third term in the same way as the second term is related to the first term.

Doctor : Patient :: Teacher : ?

Given: Doctor : Patient :: Teacher : ?

Doctor : Patient → A doctor treats a patient.
The relationship is "a professional and the person they work with or serve."
Applying the Same Logic
A teacher educates a student.
Just as a doctor works with a patient, a teacher works with a student. 

Teacher : Student
Thus, the correct option is (a) Student.