If log_Yx = (a.log_Z y) = (b.log_X z) = ab, then which of the following pairs of values for (a, b) is not possibe?

In a family gathering there are two males who are grandfathers and four males who are fathers. In the same gathering, there are two females who are grandmothers and four females who are mothers. There is at least one grandson or a granddaughter present in this gathering. There are two husband-wife pairs in this group. These can either be a grandfather and a grandmother, or a father and a mother. The single grandfather ( whose wife is not present) has two grandsons and a son present. The single grandmother (whose husband is not present) has two granddaughters and a daughter present. A grandfather or a grandmother present with their spouses does not have any grandson or granddaughter present. What is the minimum number of people present in this gathering.