Final answer:
Nelly's 2002 chart-topping hit is titled "Hot in Herre", which was a significant song of the early 2000s and contributed to the era's hip-hop and rap music popularity.
Step-by-step explanation:
The title of Nelly's 2002 chart-topping hit is "Hot in Herre". The correct answer to the multiple-choice question is option (a) "Hot in Herre". This song was a significant hit in the early 2000s and is notable for its catchy hook and Nelly's signature vocal style. It was released as part of his album "Nellyville" and quickly rose to the top of the Billboard Hot 100 chart, becoming one of the defining tracks of that summer and contributing to the popularity of hip-hop and rap music during the era.