In the grid of dots above, each dot has equal vertical & horizontal spacing from the others. A small 45-45-90 triangle

[BTGmoderatorDC]

In the grid of dots above, each dot has equal vertical & horizontal spacing from the others. A small 45-45-90 triangle is drawn. Counting this triangle, how many triangles congruent to this one, of any orientation, can be constructed from dots in this grid?
A. 112
B. 120
C. 240
D. 448
E. 480


OA B

Source: Magoosh