Identify by Marking an X in the Appropriate Column, Whether

Identify by marking an X in the appropriate column, whether each of the following items would likely serve as a source document. The first one is done as an example.
$$\begin{array} { | l | l | l | l | } \hline & & \text { Yes } & \text { No } \\\hline \text { Ex. } & \text { Credit eard } & & \mathrm { X } \\\hline \text { a. } & \text { Credit eard receipt } & & \\\hline \text { b. } & \text { Purchase order } & & \\\hline \text { c. } & \text { Invoice } & & \\\hline \text { d. } & \text { Balance sheet } & & \\\hline \text { e. } & \text { Bark statement } & & \\\hline \text { f. } & \text { Jounnal entry } & & \\\hline \text { g. } & \text { Telephone bill } & & \\\hline \text { h. } & \text { Employee earnings record } & & \\\hline\end{array}$$