Cassie Is Joining a Yoga Studio Because New Memberships Are

Cassie is joining a yoga studio because new memberships are quite inexpensive.When the director explains the plan to her,Cassie discovers that there are added costs,such as for workshops and mats.Though Cassie would not have gone to sign up if she had known the final price,she has become committed to the idea and does join the studio.The yoga studio has effectively used ________ to sell Cassie a membership.

A) social proof
B) the lowballing strategy
C) the door-in-the-face technique
D) the gradual acquiescence strategy