What is the vertex connectivity of the graph pictured below?

A graph with $10$ vertices: A$,$ B$,$ C$,$ D$,$ E$,$ F$,$ G$,$ H$,$ I, and J$.$ The graph contains undirected edges: G to I, G to D$,$ G to B$,$ I to B$,$ I to C$,$ B to C$,$ C to E$,$ C to D$,$ E to D$,$ E to H$,$ D to A$,$ D to J$,$ A to J$,$ A to F$,$ J to F$,$ J to H$.$

a$.$

$2$

b$.$

$1$

c$.$

$4$

d$.$

$3$