A recently hired network administrator has been given the task of removing SSH permissions from all compute instances in the company’s tenancy. She finds all Virtual Cloud Networks (VCNs) in the tenancy using Tenancy Explorer. She removes port 22 from the Security Lists in all VCNs. After she completes the task, the very first compute instance that she tests SSH against, allows her to still SSH into it. Why is that?
A. The VCN where that compute instance resides still has an Internet Gateway.
B. The VCN where that compute instance resides still has a route rule that allows port 22.
C. The VNIC of that compute instance is attached to a Network Security Group (NSG) that has a stateful ingress rule for all protocols on source CIDR 0.0.0.0/0.
D. The VNIC of that compute instance is attached to a Cluster Network that has a stateful ingress rule for all protocols on source CIDR 0.0.0.0/0.