Look at these two shapes.

The perimeter of the triangle is equal to the perimeter of the rectangle.
Which equation must be true
A. $3x+1 =2x+ 2x+3$
B. $3\cdot 3x+1 =2\cdot 2x+3$
C. $3(3x+1) =2( 2x+3)$
D. $3( 3x+1)=2(2x+ 2x+3)$