We were certain that the snowstorm was . . . . . . .

immutable
imminent
unavoidable
inherent

The correct answer is: B. imminent

The word “imminent” means “about to happen.” In the context of the sentence, the snowstorm is about to happen. The other options are not correct because:

  • Immutable means “unchangeable.” The snowstorm is not unchangeable, it is about to happen.
  • Unavoidable means “impossible to prevent.” The snowstorm is not impossible to prevent, it is about to happen.
  • Inherent means “existing as a permanent, essential, or characteristic part.” The snowstorm is not a permanent, essential, or characteristic part of the situation.

Therefore, the correct answer is: B. imminent.