A Transaction Has Been Recorded in the T-Accounts of Gibbs $\begin{array}{cc}\text {Cash }\\\hline\begin{array}{ll|l}&1,500& \\\end{array}\end{array}$

A transaction has been recorded in the T-accounts of Gibbs Company as follows:
$\begin{array}{cc}\text {Cash }\\\hline\begin{array}{ll|l}&1,500& \\\end{array}\end{array}$
$\begin{array}{cc}\text {Unearned Revenue }\\\hline\begin{array}{ll|l}&&1,500 \\\end{array}\end{array}$
Which of the following could be an explanation for this transaction?

A) Cash has been paid out to a company that will provide future services to Gibbs Company.
B) Gibbs has completed services for which they had earlier received cash in advance.
C) Gibbs has provided services to a customer on account.
D) Gibbs has received cash for services to be provided in the future.