Answer:
a.the number of cycles per second
Explanation:
The frequency of a sine wave is defined as the number of cycles per second.
Frequency is the inverse of the time period. The frequency of a sine wave is given by 1/TimePeriod . It is generally expressed in units of Hertz(Hz) or sec^-1. Larger the time period, lower will be the frequency and vice versa. So for higher frequency waves we need to ensure that the time period is small.