A complete n-node graph Kn is planar if and only if _____________

a-complete-n-node-graph-kn-is-planar-if-and-only-if

A complete n-node graph Kn is planar if and only if _____________
A. n ≥ 6
B. n^2 = n + 1
C. n ≤ 4
D. n + 3
The correct choice is C. n ≤ 4

Any graph with 4 or less vertices is planar, any graph with 8 or less edges is planar and a complete n-node graph Kn is planar if and only if n ≤ 4.