Select the most appropriate option to fill in blank no. 4.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1, i.e., than.
Filler Concept: When comparing two quantities, than is used.
Grammatical Explanation:
The sentence compares the recorded air quality index to what is considered ‘hazardous’.
than is the correct word for making such comparisons.
by, as, and to do not fit this comparative structure.
Correction: than
Final Sentence: …with an air quality index 23 times higher than what’s considered ‘hazardous’.
Conclusion: The correct option is than.