To determine how long the dehumidifier can run before it becomes full, we can set up the inequality based on the amount of water it removes per hour (1.6 pints) and its maximum capacity (40 pints).
Let \( h \) represent the number of hours the dehumidifier runs. The total amount of water removed after \( h \) hours is \( 1.6h \) pints. We want this amount to be less than or equal to the maximum capacity of the dehumidifier, which is 40 pints. Therefore, the inequality can be written as:
\[ 1.6h \leq 40 \]
This matches with Option #2: \( 1.6h \leq 40 \).
So the correct option is Option #2.