2023 · Q2
All offers can be connected with immediate causes, but it. _____________ whether they provide the whole explanation.
General EnglishGrammar and usage
- Ais doubted
- Bis a doubt
- Cmay be a doubt
- Dmay be doubted
Explanation
The idiomatic construction here is 'it may be doubted whether...', using 'doubt' as a verb in the passive voice to express a tentative reservation. 'Is doubted' states a plain fact and misses the hedging sense the sentence needs. 'Is a doubt' and 'may be a doubt' wrongly use 'doubt' as a noun, which cannot be followed by the 'whether' clause. Only (d) 'may be doubted' is grammatical and idiomatic.