Which of the following best defines 'integrity'?

Integrity is best defined as a firm adherence to a code of moral values. This concept encompasses honesty, consistency, and the ethical principles that guide an individual's actions and decisions. When someone possesses integrity, they demonstrate a commitment to doing what they believe is right, regardless of external pressures or popular opinion. This trait is foundational in building trust and respect, both personally and professionally.

The remaining options do not capture the essence of integrity as accurately. Following popular opinion often leads to a compromise of values instead of adhering to personal morals. The ability to maintain personal freedom speaks more to autonomy rather than moral integrity. Lastly, while loyalty to one's group can be a virtue, it does not necessarily align with the concept of integrity, which emphasizes individual moral principles rather than allegiance to a collective.