Fill in the blank with the correct word from the options given below:-

Despite his best efforts, the team's failure was _____ given their lack of preparation.

inevitable

The correct answer is Option (1) → inevitable

Inevitable – means unavoidable, something that is bound to happen. With no preparation, failure was certain.

Other options:
Avoidable – could have been prevented; opposite of the meaning here.
Improbable – unlikely to happen; failure was actually likely, not unlikely.
Optional – something done by choice; failure is not an option you choose.