Suppose a Blue Light Emitting Photons with λ = 470 $\times$

Multiple Choice

Suppose a blue light emitting photons with λ = 470 nm is rated at 60W (60 J of energy are emitted per second) .How many photons are emitted in 5.0 seconds?

A) 4.2 $\times$ 10¹⁹ photons
B) 7.1 $\times$ 10²⁰ photons
C) 1.4 $\times$ 10²⁰ photons
D) 2.1 $\times$ 10³⁸ photons
E) 1.6 $\times$ 10⁹ photons