Select the option that will improve the highlighted part of the given sentence. In case no improvement is needed, select 'No improvement required'.
Unless you carry a Covid-19 negative report, you can travel by air.

Correct option is B

The correct substitution of the highlighted words is (b) Provided.
Explanation: The sentence uses “Unless” which implies a negative condition.
However, the structure and meaning intended here is conditional — "You can travel by air if and only if you carry a negative report."
The conjunction “provided” fits best to convey a positive condition with restriction.
Grammatical rule used:
· Use “Unless” to express an exception to a rule (meaning "if not").
· Use “Provided/Provided that” to express a condition that must be met.
· Example:
· ❌ Unless you pay the fee, you can enter. (Incorrect meaning)
· ✅ Provided you pay the fee, you can enter.
�� Info Booster: “Unless” is not interchangeable with “provided.” Misusing them can lead to contradiction in sentence logic.
Why other options are incorrect:
· (a) Only – Incomplete and grammatically incorrect structure.
· (c) No improvement required – Incorrect due to mismatched logic.
· (d) Until – Implies time, not condition.