What is the origin of the name 'Bikol' according to the folk epic Ibalong?

A. It was named after Gat Ibal, a ruler of Sawangan
B. It was derived from the word 'bikod', meaning 'meandering', which described the principal river of the area
C. It was named after the people of Sawangan
D. It was named after the city of Legazpi
Answer: 