Select the option that can be used as a one-word substitute for the underlined part of the given sentence.
Dogs are known for possession of the quality of being faithful.

The phrase "the quality of being faithful" refers to faithfulness, loyalty, or accuracy in duties and relationships.
Honesty: The quality of being truthful and upright.

Genuineness: The quality of being truly what something is said to be; authenticity.

Creditability: The quality of being believable or worthy of trust.

Fidelity: Faithfulness to a person, cause, or belief, demonstrated by continuing loyalty and support.

Hence, fidelity is the correct one-word substitute.