18. Ruby: Richard, I haven’t seen you for a month. You look slimmer. Richard: Thanks! You look good too.
Ruby: How did you lose weight?
Richard: _____________
Ruby: I want to try that too.
(A) I have been working out in the gym.
(B) Being on a diet makes me hungry.
(C) My knees hurt after jogging.
(D) Exercising is boring.