15. How fast is the electron moving in the first Bohr orbit?(A) 3.3 × 10⁶ m/s(B) 5.5 × 10¹⁵ m/s(C) 4.4 × 10⁶ m/s(D) 5.5 × 10⁶ m/s(E) 2.2 × 10⁶ m/s