###
The line graph *L(G)* of a simple graph *G* is defined as follows:

- There is exactly one vertex
?(e) in *L(G)* for each edge e in *G*. - For any two edges
e and e' in *G*, *L(G)* has an edge between ?(e) and ?(e') , if and only if e and e' are incident with the same vertex in *G*.

Which of the following statements is/are **TRUE**?

(P) The line graph of a cycle is a cycle.

(Q) The line graph of a clique is a clique.

(R) The line graph of a planar graph is planar.

(S) The line graph of a tree is a tree.

*L(G)*of a simple graph

*G*is defined as follows:

*L(G)*for each edge*G*.*G*,*L(G)*has an edge between*G*.**TRUE**?

(P) The line graph of a cycle is a cycle.

(Q) The line graph of a clique is a clique.

(R) The line graph of a planar graph is planar.

(S) The line graph of a tree is a tree.

(A) P only | (B) P and R only |

(C) R only | (D) P, Q and S only |

**{{explanations.length}} Explanations**

**Explain this Question**