A) is the correct option
Step-by-step explanation:
In Psychology an ingroup is defined as the group of those people who share same particular qualities
In the given example, there are two group of people -smokers and non smokers
Smokers will share their smoking quality with other smokers whereas non smokers will share their non smoking quality with other non smokers
So smokers in this case will represent an ingroup
An outgroup does not share the same particular qualities hence smokers will be an outgroup for non smokers and vice versa
A clan is defined as group of families that have common ancestry whereas an ethnic group includes those who share same cultural background