Three of the Following Teachers Are Using Scaffolding to Help

Three of the following teachers are using scaffolding to help their students learn. Which one is not necessarily providing scaffolding?

A) Ms. Applegate gives her students a structure to follow as they write their first essay.
B) Mr. Bernardo teaches a backhand tennis swing by gently guiding each student through the correct movement a few times.
C) Ms. Chen gives her class some hints about how to solve an especially difficult word problem.
D) Mr. Donaldson takes his students on a field trip to the local art museum.