greater than or more than??

[kiranlegend]

The gyrfalcon, an Arctic bird of prey, has survived a close brush with extinction; its numbers are now five
times greater than when the use of DDT was sharply restricted in the early 1970's. .
(A) extinction; its numbers are now five times greater than
(B) extinction; its numbers are now five times more than

which option should we choose and why? what's the diff between greater than and more than?

[curmudgeon]

greater than,more than, better than, higher than...are all acceptable. It is personal choice, the meaning is the same