Which of the following terms best describes the difference between solar and mean time?

The term that best describes the difference between solar and mean time is "time discrepancies." This refers to the variations that exist between the actual solar time, which is based on the position of the sun in the sky, and mean time, which is an averaged measure that adjusts for the irregularities in the Earth's orbit and rotation.

Solar time can be affected by factors such as the Earth's elliptical orbit and its axial tilt, which cause variations in the apparent speed of the sun. Mean time mitigates these variations to create a consistent framework for timekeeping. The discrepancies arise because solar time can differ throughout the year, whereas mean time is uniform and used for standard timekeeping practices like time zones.

Other terms such as time variabilities and time dynamism may suggest changes or fluctuations but do not specifically capture the nature of the difference between solar time and mean time. Meanwhile, time equations could refer to formulas used to calculate time but do not encapsulate the conceptual understanding of the differences in timekeeping methods. Therefore, "time discrepancies" accurately embodies the concept needed to understand the distinction between these two types of time.