Which sentence contains a structural conditional error despite its explicit likelihood marker?
The vet expects the medicine to work, so if the fever falls, the foal will eat normally.
Finding the missing telescope is virtually impossible, but if we would find it, we would name the comet.✓Correct answer
I know a professional contract is highly unlikely, but if I earned one, I would leave my office job.
The courier is almost certain to come today, so if she arrives, we will send the samples.
Explanation
The telescope sentence is structurally wrong because would does not belong inside this ordinary if-clause. Its admitted remoteness calls for a past-simple condition, whereas the professional-contract sentence correctly pairs such an unlikely premise with would in the result.