As the textbook suggests, individuals do not necessarily ignore their partners' liabilities; they: 1. pretend those faults are actually assets. 2. their partners change those faults. 3. consider those faults to be less significant than other people perceive them to be. 4. consider those faults to be more significant than other people perceive them to be.

The answer is: consider such faults to be less significant than other people perceive them to be.
Often times, each partner in a long-term relationship fail to appreciate the positive traits that belong to their partner since they're used to constantly experience this positive trait. This makes them often blow up the small mistakes that their partners made way out of proportion regardless of other positive traits that could balance it out.