Maarit Takes a Course in Which She Is Tested Every

Multiple Choice

Maarit takes a course in which she is tested every two weeks.Her studying stops right after a test,followed by a gradual increase to a rapid rate of studying as the next test approaches.Which schedule of reinforcement is consistent with this example

A)  variable-ratio 
B)  fixed-interval 
C)  variable-interval 
D)  fixed-ratio