Answer:
b. become an active volunteer of find other ways to remain socially engages.
Explanation:
A person who is socially engaged in his adulthood, cannot stay alone and be at rest even in his senior citizenship. It is rare to see people accept that they are old and now they cannot do anything in these kind of people.
Once an active person is always active.
Thus, in the given instance also the retired person will search for opportunities which continuously provide him more options to be at work or contribute in career mentoring.
As these activities will keep him engaged in the social circle of people and will not make him feel lonely.