As a puppy, Cricket weighed 2 1/4 pounds. At her 1-year check-up with the vet, Cricket weighed 9.5 pounds. How much weight did Cricket gain between the time she was a puppy and her 1-year check-up? Enter your answer as a decimal or simplified mixed number.
A. 6.25
B. 12.75
C. 11.75
D. 7.25​