A businessman was comparing his company's profits for two consecutive months. In November, n, were 0.04 thousand dollars more than in December, d. The two months had a combined income of 3.15 thousand dollars. Which system of equations could be used to determine the amount of profit for each month, in thousands of dollars?

A)n+d = 3.15
n+0.04=d

B) n-3.15=d
d+0.04=n

C) d-3.15=n
n+0.04=n

D)n+d=3.15
d=0.04=n