Answer:
Participial phrase.
Explanation:
A participial phrase is a phrase that modifies a noun and contains a participle, a modifier, and other words that complete the thought. Participial phrases contain the present or past participle of the verb at the beginning of the phrase.
In the given sentence, the phrase in parenthesis modifies the noun "candidate". And the participle "obtaining" begins the phrase "obtaining the highest score".
Thus, the correct answer is a participial phrase.
