Answer: None of the men in her family are able to participate, so Mrs. Dunbar is participating in the lottery.
Step-by-step explanation:
Mrs. Dunbar is a housewife and fills up for her husband in the lottery. her husband is unable to participate this time as he has broken leg. The lottery officials ask for some other grown up boy from the family to represent in her husband, Clyde Dunbar, place.
As they don't have any such family member so Mrs. Dunbar decided to come up for the lottery on her husband's behalf.