Identify all the possible monochloro structural isomers expected to be formed on free radical monochlorination of (CH₃) 2CHCH₂CH₃.
a) 1-chlorobutane, 2-chlorobutane
b) 1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane
c) 1-chlorobutane, 2-chlorobutane, 2-methyl-2-chloropropane
d) 1-chlorobutane, 2-chlorobutane, 2-methylbutane