What is the chromatic number of compliment of line graph of bipartite graph?

(a) 0

(b) 1

(c) 2

(d) 3

The question was asked during an interview.

This interesting question is from Bipartite Graphs in portion Bipartite Graphs of Data Structures & Algorithms II

(a) 0

(b) 1

(c) 2

(d) 3

The question was asked during an interview.

This interesting question is from Bipartite Graphs in portion Bipartite Graphs of Data Structures & Algorithms II