Lucy places a box of cereal and a box of crackers together. The box of cereal has a length of 8 inches, a width of 2 inches, and a height of 10 inches. The box of crackers has a length of 6 inches, a width of 2 inches, and a height of 8 inches. What is the combined volume of the boxes?
a. 256 in.³
b. 261 in.³
c. 264 in.³
d. 267 in.³