The right answer is:
area B = area C
We can solve this problem by using Kepler's laws of planetary motion. There are three Kepler's laws. In this exercise, we need to use the second law. According to this law, a line segment joining a planet and the sun sweeps out equals areas during equals intervals of time. So, a certain planet sweeps out an area B from the point P3 to P4 in an interval of time t. On the other hand, for the same interval of time t, the planet sweeps out an area C from point P4 to P5, that is equal to the previous area according to second kepler's law.