A phrase has been given in the question and used in the sentences below. Identify the statements where the phrase has been used in a contextually and grammatically correct manner.

DARK HORSE

(I) Nobody expected her to win the competition, but she turned out to be the dark horse of the event.

(II) The painter was a dark horse, known by few but admired once his work was revealed.

(III) The farmer bought a dark horse and a white cow from the village market.

The correct option is Both (I) and (II).

Explanation:

The idiom "dark horse" refers to a candidate or competitor about whom little is known but who unexpectedly wins or succeeds. Let us analyze the usage of this phrase in the given sentences:

Sentence (I): "Nobody expected her to win the competition, but she turned out to be the dark horse of the event."
In this context, the phrase is used correctly to describe a participant who was not expected to win but ultimately succeeded, aligning perfectly with the idiomatic meaning of "dark horse."

Sentence (II): "The painter was a dark horse, known by few but admired once his work was revealed."
Here, the phrase is also contextually and grammatically correct. It refers to a person whose talents or abilities were unknown or hidden to most people, but who gained recognition and admiration once their work was revealed.

Sentence (III): "The farmer bought a dark horse and a white cow from the village market."
In this sentence, "dark horse" is used in its literal sense (a horse that is dark in color) rather than its idiomatic sense. Idiom-based questions evaluate the figurative and contextually enriched usage of the phrase. While grammatically correct in a literal sense, it does not employ the idiomatic meaning of the phrase as tested here.

Therefore, the phrase has been used in a contextually and grammatically correct idiomatic manner in statements (I) and (II).