The power of the antenna is

and since the power is the emitted energy divided by the time, the energy emitted per second is

The frequency of the emitted photons is

So the energy of a single photon is

Therefore, to find the number of emitted photons per second, we should divide the total energy emitted by the antenna in 1 second by the energy of a single photon:
20/.25 is 80, so the car will travel 80 minutes.
Answer:
a is the answer to the question
B might be the correct answer