The frequency is measured in seconds
a) True
b) False

Hint: Frequency is defined as the rate at which something occurs over a particular period of time or in a given sample, In simple words Frequency shows the time of repetition of an even which is repeating itself over a particular interval of time.
Frequency (F) = $\dfrac{1}{T}$
Where T is the time period.

Complete Step by Step solution:
The question is asking about that if a frequency is measured in time? Well, it is true that the frequency is measured in time, because according to the formula frequency is defined as per unit time or we can say that frequency is defined as Time inverse (${{s}^{-1}}$),
We have,
Frequency (F) = $\dfrac{1}{T}$

So, we can say that the frequency is a function of time

Hence our question statement is True that a frequency is measured in time
So, the correct answer is (a) True.

Additional Information:
The SI unit of frequency is Hertz, and hertz is defined as one cycle per second
So, we can say that if something has a frequency of 50 cycles per second then it will be having a frequency of 50Hz
Therefore 1Hz = 1${{s}^{-1}}$

Note:
The symbols that are used usually for frequency are $f$ and the Greek letters nu ($\nu $) and omega ($\omega $). $\nu $ is used more often when talking about EM waves, for example light, X-rays, and gamma rays. Omega ($\omega $) is used when we discuss the angular frequency—i.e., how frequently an object completes a rotation or revolution per unit time. The unit for the frequency is Hertz.