Correct Answer: b

Rationale: The phrase “Each of” takes a singular verb (“was”), and is followed by a plural noun (“participants”). Option (b) follows this correct subject-verb agreement rule.

Correct Answer: b

Rationale: The correlative conjunction pair “Scarcely… when” is used, and it requires inversion (“had she stepped”) in the main clause. Option (b) properly pairs “Scarcely… when”.

Correct Answer: c

Rationale: The structure “One of + plural noun” takes a singular verb. “One of my friends” takes the singular verb “is”.

Correct Answer: A

Rationale: “Hardly” is correctly paired with “when” and uses subject-verb inversion (“Hardly had the meeting begun”).

Correct Answer: C

Rationale: “No sooner” requires “than” (not when) and must be followed by inversion (“had the bell rung”) along with consistent past tense verbs (“rushed”).

Correct Answer: C

Rationale: “The number of” takes a singular verb (“has”). (Note: “A number of” takes a plural verb, but “The number” treats it as a singular entity).

Correct Answer: B

Rationale: “A series of” is a collective phrase treated as a singular grammatical subject, requiring the singular verb “was”.

Correct Answer: C

Rationale: This is a Third Conditional sentence expressing an unreal past situation. Structure: If + past perfect (“had worked”), main clause + would have + past participle (“would have succeeded”).

Correct Answer: A

Rationale: The adjective “proficient” appropriately takes the preposition “with” when referring to tools or instruments (alternatively “in” when referring to a subject/skill).

Correct Answer: (B)

Rationale: “The pack” is a singular collective noun acting as a single unit, hence it requires the singular verb “was”.