Use the Riemann Sum Corresponding to a Subdivision of the Rectangular

Multiple Choice

Use the Riemann sum corresponding to a subdivision of the rectangular region R defined by 0 $\le$ x $\le$ 6, 0 $\le$ y $\le$ 4, into six squares of edge length 2 and sample points at the upper-right corner of each square to estimate .

A) 72
B) 288
C) 144
D) 36
E) 168