Which one is appropriate?

[meridiem.d]

Could you tell me the correct answer and explain the difference?

There are many grouping methods _________ average and below average students may benefit as well as gifted do.

a) from which
b) which

[Mister Micawber]

.
From which.

There are many grouping methods from which average and below average students may benefit as well as gifted do =

Average and below average students may benefit from many grouping methods as well as gifted [students] do.
.

[RonBee]

Could you tell me the correct answer and explain the difference?

There are many grouping methods _________ average and below average students may benefit as well as gifted do.

a) from which
b) which

The key, I think, is the word from. That is, one benefits from something. You could rearrange the letters in the sentence, but you have to keep the word from. Example:

There are many grouping methods which average and below average students may benefit from as well as gifted students do.