An instructor is beginning a course and wants to measure the level of expertise of the learners. Which of the following is the BEST method for measuring the level of understanding over the course material? 

Answer options:

A. Ask the learners about their level of understanding over the course material.
B. Assume that the class has a medium level of understanding over the course material.
C. Deliver a pre-test covering the course objectives.
D. Ask another instructor who has taught the learners before.

C