WFO Corporation Has Gross Receipts According to the Following Schedule

WFO Corporation has gross receipts according to the following schedule:
If WFO began business as a cash-method corporation in Year 1, in which year would it have first been required to use the accrual method?
$$\begin{array} { | l | l | } \hline \text { Year 1 } & \$ 2 \text { million } \\\hline \text { Year 2 } & \$ 4 \text { million } \\\hline \text { Year 3 } & \$ 6 \text { million } \\\hline \text { Year 4 } & \$ 4.5 \text { million } \\\hline \text { Year 5 } & \$ 5 \text { million } \\\hline \text { Year 6 } & \$ 7 \text { million } \\\hline\end{array}$$

A) Year 3
B) Year 4
C) Year 5
D) Year 6
E) None of these