Correct option is B
Given Word: Mainstreaming
The letters in Mainstreaming are:
A, A, G, I, I, I, M, N, N, N, R, S, T, M
A, A, G, I, I, I, M, N, N, N, R, S, T, M
Check Each Option:
A) Tempting
The letter P is not in "Mainstreaming".
B) Training
"Mainstreaming" contains all these letters in sufficient quantity. (Follow)
C) Maintaining
Only two "A"s, but "Maintaining" requires three.
C) Streamed
The letter D is not in "Mainstreaming".
So, Training can be formed.
Thus, the correct option is: (b) Training