At some temperatures, the relative reactivities of 3°,2° and 1° alkane hydrogens in free radical chlorination are in the ratio of 5: 3: 1. thus, monochlorination of isopentane should produce these percentages of 2 chloro-2-methylbutane (a), combined 1-chloro- 2-methylbutane and (b), and 2-chloro-3-methylbutane (c: a) 8% a, 75% b, 17% c b) 25% a, 45% b, 30% c c) 29% aa, 44% b, 18% c d) 30% a, 35% b, 35% c f) 36% a, 43% b, 21% c