Common Activity Levels of Radon-222 Are in the Range of 1

Common activity levels of radon-222 are in the range of 1 picocurie/liter (pCi/L) at room temperature and pressure. How many atoms of radon decay each minute in a 1 L sample of gas with radiation at this level? Recall that 1 Bq = 1 decay/s and 1 Ci = 3.7 $\times$ 10¹⁰ Bq.

A) 6 $\times$ 10^-4
B) 6 $\times$ 10⁸
C) 2 $\times$ 10¹²
D) 2
E) 4 $\times$ 10^-2