The fire-fighters made every effort to put off the flames. The building burned down completely

Explain:

Firefighters did their best to put out the fire. The building was completely burned down.

A. By all means put out the fire, the firefighters completely burned down the building.

B. Without the efforts of the firefighters, the building would have completely burned down.

C. The building was completely burned down despite the best efforts of the fire brigade to put out the fire.

D. Due to the efforts of the firefighters to put out the fire, the building was completely destroyed.

→ Choose the answer C