Helen has a rectangular garden that is $x$ meters wide and $y$ meters long. She wants to increase the length by 10 meters and decrease the width by 2 meters. Which of the following expressions could she use to represent the new perimeter in meters? Select one: A. $x+y+8$ B. $2 x+2 y+8$ C. $2 x+2 y-16$ D. $2 x+2 y+16$

Step 1 ：Helen has a rectangular garden that is $x$ meters wide and $y$ meters long. She wants to increase the length by 10 meters and decrease the width by 2 meters.

Step 2 ：The perimeter of a rectangle is given by the formula $2*(length + width)$. In this case, Helen wants to increase the length by 10 meters and decrease the width by 2 meters. So the new length will be $y+10$ and the new width will be $x-2$.

Step 3 ：Therefore, the new perimeter will be $2*((y+10) + (x-2))$.

Step 4 ：Let's simplify this expression and see which option it matches with.

Step 5 ：The simplified expression for the new perimeter is $2*x + 2*y + 16$. This matches with option D.

Step 6 ：Final Answer: \(\boxed{D. 2x + 2y + 16}\)