Fill in the blank with the most appropriate option:
Rarely ____ witnessed such unanimous agreement among reviewers.

Question

Accepted Answer

**Brief explanation**

1. "Rarely" is a negative adverb that requires subject–auxiliary inversion. 
2. The natural phrase is: **"Rarely has there been such unanimous agreement among reviewers."**
3. Option **(a)** fits this correct inverted form. 
4. Other options are less natural or ungrammatical here.

FINAL_ANSWER: a

Answer

Answer

Answer