Answer:
The correct option is A.
Explanation:
It is given that for a birdhouse, he needs one of these shapes:
a) 2 trapezoid
b) 1 square
c) 2 triangles
d) 4 rectangles
To make 8 birdhouse the number of required trapezoids is

It means for 8 birdhouse, he will need 16 trapezoids. Therefore option A is correct.
To make 12 birdhouse the number of required rectangles is

It means for 12 birdhouse, he will need 48 rectangles. Therefore option B is incorrect.
The ratio of trapezoids to squares is

The ratio of trapezoids to squares is 2 to 1. Therefore option C is incorrect.
The ratio of squares to triangles is

The ratio of squares to triangles is 1 to 2. Therefore option D is incorrect.