B and E are the answers I would choose.
On the left side, you have 2 nitrogen. On the right, you only have one. So put a 2 in front of the NH3. That gives you balanced nitrogen.
After that step, you have 6 hydrogen (the coefficient x the subscript) on the right, so you need to get 6 on the left. You have 2 hydrogen (subscript). 6/2 = 3, so put a coefficient of 3 in front of the H2, and you’ll have 6 hydrogen.
Your balanced equation is N2 + 3H2 -> 2NH3
Please lmk if you have questions.
