Sam is conducting a science experiment about the effects of fertilizer on the growth of a plant. In week 1, his plant grew 12.26 centimeters. In week 2, his plant grew 7 centimeters. In week 3, his plant grew 5.79 centimeters.
What was the total growth of his plant during the 3 weeks?
 A. 18.12 centimeters
 B. 24.65 centimeters
 C. 24.95 centimeters
 D. 25.05 centimeters