How many members of both Spanish club and French club are female?
Its an overlap set question and it asks about number of female members who are part of both Spanish and French clubs.
(1) There were 21 females present at a joint meeting of the members of the Spanish and French clubs, and the only members absent were male.
From this we know that there are 21 females present but we don't know how many members were part of both the clubs.
Not sufficient
(2) The Spanish club has 14 female members and the French club has 9 female members.
Again, we don't know how many members were part of both the clubs.
Not sufficient
Statement 1 and 2 together
total female members = 14 + 9 = 23
but 21 females are present at a joint meeting of the members of the Spanish and French clubs
therefore, the number of female members part of both the clubs = 23 - 21 = 2
Sufficient
Answer C