Hey there! I'm happy to help!
Let's use the distributive property to undo the parentheses. We multiply the number next to the parentheses by each number inside of the parentheses.
-7+3(-4e-3)
-7-12e-9
We combine like terms.
-16-12e
This means that Answer B is incorrect. Answer A could still be correct though as it could have equal value to -16-12e.
-4(3e+4)
We use distributive property.
-12e-16
We see that these have the same value, so the correct answer is A.
Have a wonderful day! :D