To solve the equation \( 173f - 1 = 1 \), we'll follow these steps:
1. Add 1 to both sides of the equation:
\[
173f = 1 + 1
\]
\[
173f = 2
\]
2. Divide both sides by 173:
\[
f = \frac{2}{173}
\]
Since \( \frac{2}{173} \) does not equal 6, 3, 4, or 5, none of the provided options are correct based on this calculation.
Please verify the question or the options provided.