Correct option is A
Option (a) contains an error.
Error Explanation: The phrase should be “ a thrilling finish,” not just “thrilling finish.” The article ‘a’ is missing before the singular countable noun “finish.”
Correct phrase: In what turned out to be a thrilling finish
Grammatical rule used:
· Singular countable nouns must be preceded by an article (a, an, the) unless modified by other determiners.
· Example: It was a great match. NOT "It was great match."
· Information booster: Article omission errors are frequently tested in exams, especially before singular nouns and adjectives.