The first card selected from a standard 52-card deck is a king

The first card selected from a standard 52-card deck is a king.

a. If it is returned to the deck, what is the probability that a king will be drawn on the second selection?
b. If the king is not replaced, what is the probability that a king will be drawn on the second selection?
c. What is the probability that a king will be selected on the first draw from the deck and another king on the second draw?