Final answer:
The Beatles song that reflects the teen thoughts and emotions of the early '60s is "I Want to Hold Your Hand." It symbolizes young romance and helped define the band's early style, as well as contributing to the British Invasion and Beatlemania.
Step-by-step explanation:
The lyrics of the Beatles song that reflect the teen thoughts and emotions of the early '60s and show the group's evolving style are from "I Want to Hold Your Hand". This song marked a turning point in the Beatles' career and in popular music of the era. Its upbeat tempo, catchy melody, and innocent lyrics focused on holding hands as a symbol for young romance perfectly encapsulated the feelings and social norms of the time period.
Released in 1963, "I Want to Hold Your Hand" was a smash hit and became emblematic of the Beatles' early period. It was also one of the key songs that ushered in the British Invasion of the United States and the worldwide Beatlemania phenomenon.
Therefore, the correct answer to the provided options is d. "I Want to Hold Your Hand".