A flash of red light and a flash of blue light enter a glass cube perpendicular to its surface at the same time. After passing through the block, the pulse exits first.

One number is said to be an "order of magnitude" larger than another number if choose one: a. it is 10 times larger. b. it is 5 times larger. c. it is 3 times larger. d. it is 100 times larger. e. it is 2 times larger.