The following sum is a right Riemann sum for the definite integral where a = 4 and b = (16 - x). The limit of these Riemann sums as n tends to infinity is:
a) ∫(16 - x) dx from 4 to 16
b) ∫(16 - x) dx from 0 to 16
c) ∫(16 - x) dx from 4 to 0
d) ∫(16 - x) dx from 16 to 4