If someone is described as obdurate, which of the following best captures their character?

Describing someone as obdurate indicates that they are hardened in their feelings or attitudes, particularly in relation to being unyielding or resistant to persuasion. The term comes from a context where an individual displays stubbornness or inflexibility, especially when it involves moral or emotional matters.

In this scenario, "hardhearted" aligns perfectly with the definition of obdurate, as it highlights a lack of empathy or emotional responsiveness. This characterization captures the essence of someone who is unbending and unwavering in their stance or feelings, often disregarding appeals for compassion or change.

The other descriptors, such as being easily swayed, flexible, or forgiving, directly contrast with the notion of being obdurate. Someone who is easily swayed or flexible would indicate a willingness to change their mind or adapt their views, while being forgiving implies a readiness to let go of resentment or animosity—qualities that are antithetical to the hardheartedness associated with being obdurate. Thus, the strong alignment of "hardhearted" with the essence of the term makes it the best choice.