Choose the appropriate word to fill in the blank in the given sentence:

The rank and _____ of the party had turned against the leader.

1. class
2. officers
3. file
4. people

Option 1 -> "Rank and class" is not a standard English idiom and doesn't convey a clear meaning in this context.

Option 2 -> "Rank and officers" is redundant since rank typically refers to hierarchical positions that officers hold.

Option 3 -> "Rank and file" is an established idiom meaning the ordinary members of an organization, distinct from its leadership.

Option 4 -> "Rank and people" is not idiomatic and sounds grammatically awkward.

Hence, Option 3: file -> "Rank and file" is a fixed English expression that refers to the ordinary members or common people within an organization or group, as opposed to the leaders. In this sentence, it indicates that the general party members (not just the leaders) had turned against the leader -> correct