Answer:
c. 3
Step-by-step explanation:
Dicholorination of tertiary alkane ( i.e. isobutane) is a halogenation reaction which makes it possible to replace the alkyl functional group with halogenated chlorine.
When Isobutane is subjected to free radicals chlorination, three distinct dichlorination can be formed.
The mechanism of the formation of these products can be seen in the image attached below.