The Journal Entry to Record the Completion of a Contract

The journal entry to record the completion of a contract in a job costing system for a service firm is:
$$\begin{array} { | l | l | l | l | } \hline \text { A } & \text { Cost of Services Billed } &\text { x x x }& \\\hline & \text { Wages Payable } & & \text {x x x} \\\hline\end{array}$$
$$\begin{array} { | l | l | c | c | } \hline \text { B. } & \text { Work-In-Process Inventory } & \text {x x x} & \\\hline & \text { Wages Payable } & &\text { x x x} \\\hline\end{array}$$
$$\begin{array} { | l | l | c | c | } \hline \text { C. } & \text { Cost of Services Billed } &\text { x x x }& \\\hline & \text { Work-In-Process Inventory } & & \text {x x x} \\\hline\end{array}$$
$$\begin{array} { | l | l | c | c | } \hline \text { D. } & \text { Finished Goods Inventory } & \mathrm { xxx } & \\\hline & \text { Wark-In-Process Inventory } & & \mathrm { xxx } \\\hline\end{array}$$

A) Option A
B) Option B
C) Option C
D) Option D