B). Chocolate is now a sweet treat that is very popular in the United States.
Explanation:
The second statement most aptly relates the two given facts. It <u>states that chocolate has now become a sweet treat(implies that 'it wasn't sweet treat earlier despite being there since ancient times') and has become quite popular as reflected by huge consumption of '3 billion pounds' every year</u>. Thus, the second option amalgamates the two facts and displays that how the latter has led to former and how the former led to bring change in the latter by making it a popular sweet treat in the United States. Therefore, <u>option B</u> is the correct answer.
