Choose the sentence that the word(s) that is CLOSEST in meaning to the underlined part: The first year at college was the most challenging time of his life, but he thoroughly enjoyed it.
Thoroughly: completely, perfect = completely
The remaining answers:
A. suddenly: suddenly
B. immediately: immediately
D. thoughtfully: thoughtfully, thoughtfully
The first year at university was the most challenging time of his life, but he thoroughly enjoyed it.