Two puppies,Walter and Stanley, are growing at different but constant rates. Walter’s mass is 12\:kg and he is growing at a rate of 2\:kg/month. Stanley’s mass is 6\:kg and he is growing at a rate of 2.5\:kg/month. What will Stanley’s mass be when it is equal to Walter’s?
Answer Choices
A. 24\:kg
B. 28\:kg
C. 32\:kg
D. 36\:kg
E. 42\:kg