User

You have an azure subscription that includes the following resources:

$-$ Vnet$1,$ a virtual network

$-$ Subnet$1,$ a Subnet in VNET$1$

$-$ Webapp$1,$ a web app application service

$-$ NSG$1,$ a network security group

You create an application security group named ASG$1$

Which resource can use ASG$1$

a$.$ VNET$1$

b$.$ Subnet$1$

c$.$ Webapp$1$

d$.$ NSG$1$