Polypropylene is made by polymerizing propene, C₃H₆ (m = 42.1). How many molecules of propene must be polymerized to make 3.50 g polypropylene?
a) 5.90 x 10²⁴
b) 1.67 x 10²⁴
c) 1.40 x 10²⁴
d) 8.33 x 10²³