Correct option (b) There is at least one supporter of `party Y' who knew some supporters of 'party X' as a friend.
Explanation:
From the data given, we know
1. some supporters of party X -> knew Z -> none agreed for alliance with party Y
2. some supporters of party X -> knew Z -> some had friends in party Y
Option (a) is incorrect because we are not given information about opinion of supporters of party Y Similarly, given data does not support option (c) or (d)
From 2, we can say that “There is at least one supporter of `party Y' who knew some supporters of 'party X' as a friend”.