Which of the Following Is the Best Example of Scaffolding

Which of the following is the best example of scaffolding?

A) Ms. Chow first models how to make a capital letter in cursive at the board, then she provides a worksheet that groups can work on that offers tracing opportunities before she asks them to write each letter on their own.
B) Mr. Osaka takes students to the museum.
C) Mr. Thompson ensures a full understanding on the part of his students before advancing to the next subject.
D) Mrs. Donaldson ensures curriculum materials are developmentally appropriate before suggesting them to colleagues who teach children at different ages from her students.