Find the part of the given sentence that has an error in it.
One of the most common causes of anosmia and hyposmia is a virus that producing upper respiratory infections.

Option (d) contains an error.
Explanation:
1. The clause "that producing upper respiratory infections" is grammatically incorrect.
2. "Producing" should be replaced with "produces" to make the verb finite and match the subject "virus."
3. A relative clause must have a finite verb (produces), not a gerund or participle (producing), to make sense.
4. The sentence implies that the virus is currently causing infections, so the present tense "produces" is correct.
Hindi Explanation: "Producing" को "produces" से बदलना होगा। यह एक finite verb है जो subject "virus" के साथ मेल खाता है। Corrected sentence: One of the most common causes of anosmia and hyposmia is a virus that produces upper respiratory infections.