Stalactites-The Long, Icicle-Like Formations That Hang from the Ceilings of Caves-Are

Stalactites-the long, icicle-like formations that hang from the ceilings of caves-are formed from recrystallizing minerals like calcite (calcium carbonate) .The K_sp of calcium carbonate is 4.5 *10^-9.What is the concentration of a saturated calcium carbonate solution?

A) 1.0 * 10^-3 M
B) 4.5 *10^-9 M
C) 6.7 * 10^-5 M
D) 2.3 * 10^-9 M
E) 4.5 * 10^-5 M