Kiely's Mother Is Paying Her to Read This Summer

Kiely's mother is paying her to read this summer.For every chapter of David Copperfield that she reads and prepares a written synopsis of in one and one-half hours or less,she receives $3.If she completes the task in more then the allotted time she receives only $2.What payment plan is Kiely's mother using to encourage Kiely to read at the faster rate?

A) the differential piece rate plan
B) the standard hour plan
C) the merit pay plan
D) the base rate plus standard output plan
E) the commission plan