A Flux of 10¹⁴ N/m² · S Is Incident on an

A flux of 10¹⁴ n/m² · s is incident on an foil that is 0.10 cm thick.The density of aluminum is 2.7 $\times$ 10³ kg/m³.The number of neutrons reacting with the aluminum is 10⁶ n/m² · s.The cross section for this reaction is approximately

A) 10⁴ barn
B) 10^-6 m²
C) 1.7 $\times$ 10^-34 m²
D) 6.6 $\times$ 10^-32 m²