Final answer:
The Moon engages in synchronous rotation, completing one rotation on its axis in the same amount of time it takes to orbit the Earth, thus keeping the same face toward the Earth at all times. The correct answer is that the Moon rotates once per month.
Step-by-step explanation:
The Moon rotates on its axis in exactly the same time that it takes to revolve around the Earth, a phenomenon known as synchronous rotation.
As a consequence of this synchrony, the Moon always keeps the same face, the 'near side', pointed toward Earth. This is why we only see one hemisphere of the Moon from our vantage point on Earth.
To illustrate, you can perform a simple simulation by revolving around another person while spinning at the same rate. As you do this, you'll find that you continuously face them, mimicking the Moon's behavior.
The Moon completes one rotation for each revolution around Earth, meaning it rotates once per month, which is why option 1) It rotates once per month is the correct answer.