General exam question G8A13

WhyA link budget is the sum of transmit power and antenna gains minus system losses as seen at the receiver. A link budget tallies every gain and loss a signal experiences end to end, transmit power plus antenna gains, minus feed line, path, and other system losses, to predict the signal level that actually arrives at the receiver, answer C. It isn't a financial cost estimate, and it's more than just antenna gains minus losses (transmit power has to be part of the sum too), so A and B are incomplete, and D's simple transmit-power-minus-sensitivity subtraction skips the gain and loss terms a real link budget accounts for.