(a)

(b) The two links are control (dynamic) link and access (static) link.

Control (Dynamic) link points from the callee function to the activation record of the caller function, providing the program the correct address to continue after returning from the callee function.

Access (Static) link points from the function to the most recent activation record of the innermost function that defines this function. It helps to implement the lexical scope.

(c)