Step-by-step explanation: Imagine you have the following generic trinomial

to find two binomials "x+n" and "x+m" for the trinomial above we just need to find the values for "n" and "m". We know that

So finally we just need to find two numbers that the sum gives us the value of "b" and the product gives us the value of "c".
Step 1: Identify the variables
Once b = 3 and c = -28 we just need to find two numbers that the sum is equal to 3 and the product is equal to -28
Step 2: Now we can see that

As we can see above the two numbers are -4 and +7.
Final answer: So the two binomials are
A. x-4 and C. x+7