Once I forgot the piece of paper on which the name of the hotel was written, I was as . . . . . . . . as lost.

Answer: Option C

The sentence uses the common comparative structure “as … as”, which requires an adjective that logically fits the meaning.

The idiomatic expression “as good as lost” is commonly used to indicate that someone is completely lost or in a hopeless situation.

Options like much and sure do not fit grammatically in this structure, and “as bad as lost” is not a standard expression.

Therefore, the correct and meaningful completion is “as good as lost”, making Option C the correct answer.