On June 1, 2019, an Advance Rent Payment of $8,400

On June 1, 2019, an advance rent payment of $8,400, representing a four-month prepayment for the months of June, July, August, and September, was received in cash from the company's tenant. The adjusting entry that will be made at the end of each month to show the amount of rent "earned" during the month is:

A) $$\begin{array} { | c | l | c | c | } \hline \text { Dr. } & \text { Cash } & 2,100 & \\\hline \text { Cr. } & \text { Rent Revenue } & & 2,100 \\\hline\end{array}$$
B) $$\begin{array} { | c |l| c | c | } \hline \text { Dr. } & \text { Cash } & 8,400 & \\\hline \text { Cr. } & \text { Unearned Rent Revenue } & & 8,400 \\\hline\end{array}$$
C) $$\begin{array} { | c | l | c | c | } \hline \text { Dr. } & \text { Unearned Rent Revenue } & 6,300 & \\\hline \text { Cr. } & \text { Rent Revenue } & & 6,300 \\\hline\end{array}$$
D) $$\begin{array} { | c | l | c | c | } \hline \text { Dr. } & \text { Unearned Rent Revenue } & 2,100 & \\\hline \text { Cr. } & \text { Rent Revenue } & & 2,100 \\\hline\end{array}$$