There are four students in a class namely A, B, C and D. A tells that a triangle is a bipartite graph. B tells pentagon is a bipartite graph. C tells square is a bipartite graph. D tells heptagon is a bipartite graph. Who among the following is correct?

(a) A

(b) B

(c) C

(d) D

The question was asked in class test.

I'm obligated to ask this question of Bipartite Graphs topic in section Bipartite Graphs of Data Structures & Algorithms II