D... Breakers work via thermal. The juice flowing through them heats the breaker and eventually heats it enough to flip it... Eventually with numerous trips the breaker will weaken and begin to trip more...
Also with all over that running you will start getting up over 70 amps. We always say to not hit these amperage of a circuit, just for a margin of error. So a 17.5amp load I woul put on a 30amp circuit, despite it being <20amps. Combine those two factors and it will trip more often. Have an electrician come replace the main and double check it all.
Also, make sure the filters and coil are clean on your ac. The more efficient it is, the less draw. Same for the coils on your ac.
Call me if you need me to clarify anything!
