Final answer:
Gawain's third encounter with Lady Bertilak in 'Sir Gawain and the Green Knight' presents a significant test of his loyalty and chastity. The quote 'His heart heaved for pity' (option C) suggests he almost accepts Lady Bertilak's gift, indicating that he nearly falters in maintaining his knightly vows.
Step-by-step explanation:
Gawain's third encounter with Lady Bertilak tests his chivalric values and his resolve to maintain his chastity and loyalty. He is propositioned by Lady Bertilak who attempts to seduce him, thereby testing his adherence to his knightly vows. The narrative of Sir Gawain and the Green Knight builds tension as Gawain tries to resist the temptations presented by Lady Bertilak.
The answer to the student's question is option C: Gawain almost accepts Lady Bertilak's gift; "His heart heaved for pity." This quote supports the idea that Gawain's resolve is tested and he nearly crosses the line of fidelity. His emotional response, described as his heart heaving for pity, indicates his struggle and the temptation he faces in remaining faithful to his vows.