[单选题]
The half-life of radioa1di6 ko ms7t3q 3t5prmctive iodine-137 is 8.0 d+n0 a4d:l)qkg uim s7bays. How many iodine nuclei are nelq:) mgbs4du +i0nk a7cessary to produce an activity of $1.0 \; \mu Ci$?
A. $2.9 \times 10^{9}$
B. $4.6 \times 10^{9}$
C. $3.7 \times 10^{10}$
D. $7.6 \times 10^{12}$
