Answer :
Final answer:
The Kingston Trio won a Grammy award in 1959 for their hit song "Tom Dooley" in the Country Music category, hence the correct option is d) 1959.
Explanation:
The Kingston Trio won a Grammy award in the Country Music category for their hit song "Tom Dooley" in the year 1959, despite the absence of a specific Folk category at that time. The song "Tom Dooley" became a massive folk hit and played a significant role in popularizing the folk music movement in the United States.
Winning the Grammy award not only highlighted the Kingston Trio’s contribution to music but also underscored the merging of folk elements into mainstream genres, leading to greater recognition and appreciation of folk music.