According to Kepler's laws of planetary motion, specifically the third law, planets that are closer to the star will have shorter orbital periods and, generally, will move faster in their orbits compared to planets that are farther away.
Therefore, the correct description is:
The orbital period of Planet A is shorter than that of Planet B.
In addition, it's also true that the average speed of Planet A is greater than that of Planet B, but that option is not listed here.