All three vertices of \triangle A B C lie on the parabola defined by y=x^{2}, with A at the origin and \overline{B C} parallel to the x-axis. The area of the triangle is 64 . What is the length B C ?

**Answer Choices**

A. 4

B. 6

C. 8

D. 10

E. 16

All three vertices of \triangle A B C lie on the parabola defined by y=x^{2}, with A at the origin and \overline{B C} parallel to the x-axis. The area of the triangle is 64 . What is the length B C ?

**Answer Choices**

A. 4

B. 6

C. 8

D. 10

E. 16