ANSWER and EXPLANATION
(a) When a skydiver is beginning her fall, the only force acting on her will be her weight acting downwards. Hence, the full-body diagram is:
(b) When her parachute opens, air resistance also acts strongly on her in the upward direction along with her weight. Hence, the full-body diagram is:
(c) A couple of seconds after, while she is midair, her weight along with air resistance (although not as strong as the instant the chute is opened) still acts on her. Hence, the full-body diagram is: