Final answer:
The best words to describe the author's tone in the given paragraph are 'sentimental and tender' as it reflects a gentle and affectionate remembrance.
Step-by-step explanation:
The author's tone in the paragraph "He remembers his grandmother's last words were, 'I'm sorry we didn't get to celebrate Thanksgiving, Jake.' And every year, even after 27 years, he could never get himself to celebrate Thanksgiving." can best be described as sentimental and tender, option c. This is evident due to the emotional connection and lasting impact of a family member's last words affecting personal traditions. The tone reflects a gentle and affectionate remembrance rather than feelings of hopelessness, anger, or indifference.