Answer:
D. Infinitely many
Explanation:
In this case, the number of equilateral triangles we could make is restricted by the length of its sides. However, this problem doesn't restrict any side, it doesn't specifies a length for all sides, it only gives the angles, which have to be equal to 60° because it's a equilateral triangle.
This means that we could make infinitely many triangles with angles of 60°, it could be a triangles with sides of 1 unit long, 2 units, or 100 units long, all of them would have angles of 60°.
Therefore, the right answer is D.