Determine whether the following problem involves a permutation or combination. (It is not necessary to solve the problem.

Determine whether the following problem involves a permutation or combination.​ (It is not necessary to solve the​ problem.)

A medical researcher needs 49 people to test the effectiveness of an experimental drug. If 194 people have volunteered for the​ test, in how many ways can 49 people be​ selected?

A. Permutation

B. Combination