Why is it necessary to create a Security Group when launching an instance in a custom VPC?

What is the role of route tables in a custom VPC?

Why do we need to create subnets inside a custom VPC?

Which of the following cannot span multiple Availability Zones?

a) VPC

b) Subnet

c) Route Table

d) Internet Gateway

What steps are needed to make an EC2 instance in a public subnet accessible from the internet?