To Start a Mobile Dog-Grooming Service, a Woman Borrowed $2,400

To start a mobile dog-grooming service, a woman borrowed $2,400. If the loan was for 2 years and the amount of interest was $120, what simple interest rate was she charged?

A) 2.1%
B) 2.5%
C) 2.8%
D) 2.3%
E) 2.4%