A company is paying a local television station to run its commercials. The cost for running commercials is a one-time campaign fee and also a per-second fee for the air time of each commercial. The cost can be modeled by the equation y = 500 + 50x where x is seconds.

What is the y-intercept and what does it represent?

A500; it represents the per-second fee of air time

B500; it represents the one-time campaign fee

C50; it represents the per-second fee of air time

D50; it represents the one-time campaign fee