Toby weighed 57.6 kg. He got sick and lost 2.4 kg in the first week, then 1.7 kg more in the second week. When he got well, he gained 3 kg in the third week. What was his weight after three weeks?

A. 54.5 kg
B. 55.5 kg
C. 56.5 kg
D. 57.5 kg​