Which option correctly completes the sentence: Firefighters had ___ put out the fire.

• A. Been able
• B. Been unable
• C. Are able
• D. Was unable

Answer: (B)

The sentence uses the past perfect with a form of “be able/unable” to express what was true for firefighters up to a past moment. Filling the blank with “been unable” gives: “Firefighters had been unable to put out the fire.” This clearly communicates that by that past point, they could not extinguish the fire.

Using “been able” would imply they could put it out by that time, which can change the meaning in a narrative about a difficult fire. Other options don’t fit the tense or meaning: present tense forms (“are able”) don’t match the had/ past perfect structure, and the simple past form (“was unable”) doesn’t align with the auxiliary “had” in this sentence.