How Many ¹⁴C Atoms Are in a Charcoal Sample That

How many ¹⁴C atoms are in a charcoal sample that has a decay rate of 3500 disintegrations per min? (For ¹⁴C, t_1/2 = 5730 yr.)

A) 2.9 × 10⁷ atoms
B) 8.0 × 10^-7 atoms
C) 1.4 × 10¹⁴ atoms
D) 1.5 × 10¹³ atoms
E) 6.02 × 10²⁰ atoms