The Alpha Particles Emitted by Radon-222 Have an Energy of 8.8

The alpha particles emitted by radon-222 have an energy of 8.8 * 10^-13 J. If a 200. g Pb brick absorbs 1.0 * 10¹⁰ alpha particles from radon decay, what dose in rads will the brick absorb

A) 3.6 rad
B) 4.0 rad
C) 4.4 rad
D) 4.8 rad
E) None of the above