Many studies over many years have replicated Piaget's results on tasks such as object permanence and conservation, under the condition that

A) the instructions are presented in English.
B) the child's parent is present during testing.
C) the experimenters conduct the tasks in the same ways as Piaget conducted them.
D) only firstborn children are tested.

C) the experimenters conduct the tasks in the same ways as Piaget conducted them.