we have the expression
11.5x(x+3)+350
this is the same that
11.5(A)+350
where A is the area of rectangular room
11.5 is the rate per square feet
350 is the fee for materials
therefore
the answer is
11.5 represent -----> option E
x(x+3) ------> option F
350 -----> option B
x -----> option C
x+3 ----> option D