Hi what is the answer

(3x+4)^2

Step-by-step explanation:

You do 3 multiplied by x (the number you are thinking of) which becomes 3x.

Then, you add 4 to it, which would then bring the equation to 3x+4.

Finally, when you square it, to do that the initial equation (3x+4) has to be in parenthesis like so:   (3x+4)^2

and to do the square with a keyboard you do Shift+6 and it will give you this sign ^ and that is to indicate you are squaring something

a. is correct