Choose the correct collective noun for the phrase given below.
A ________ of keys.

- Bunch: It is the collective noun used with plural nouns such as 'keys', 'grapes' etc.
- Flock: It is the collective noun used with plural nouns such as 'sheep', 'birds' etc.
- Fleet: It is the collective noun used with plural nouns such as 'ships', 'cars'. etc.
- Pride: It is the collective noun used with the plural noun 'lions'.