Hey, there!
The parentheses would make it multiplication
The word sum means add
A number was unknown, so we will label it as "x"
So, let's see what we're working with here!
If you chose "Option A" the question would be "five multiplied by a number and the sum of 3" (that doesn't give you the right answer"
For B. same thing with option A
For "Option C" its not asking you "a number with sum of three times five"
So, this leaves "Option D." as your answer because 3 is getting multiplied by the sum of some number and five
Good luck on your assignment and enjoy your day!
~MeIsKaitlyn:)