Final answer:
The frequency of a simple pendulum does not depend on its mass, but rather on its length and the acceleration due to gravity.
Step-by-step explanation:
The frequency of a simple pendulum does not depend on the mass of the pendulum. In physics, we learn that the period and frequency of a simple pendulum are influenced by its length and the acceleration due to gravity. The period (T), given by the formula T = 2π√(l/g), where l is the pendulum's length and g is the acceleration due to gravity, is completely independent of its mass. It is also relatively independent of amplitude, particularly when the amplitude is less than about 15°.
Therefore, the correct answer to the student's question is 'A. its mass'. Even simple pendulum clocks can maintain their accuracy as the period is unaffected by the pendulum's mass.