Which statement about $4$ G wireless communications is correct?

a$.$ Eventually, $4$G will make worldwide roaming as well as universal access possible.

b$.$ The bandwidth and latency of $4$ G networks enable rapid streaming of VR content.

c$.$ A twctrour movie can be streamed in less than $3$ seconds over a $4$ G network.

d$.$ Major $4$G networks use circuit$-$switching rather than packet$-$switching approaches.