The correct answer is 'Yes' (A) because modifying a Network Security Group (NSG) is sufficient to allow HTTP traffic (port 80) from the internet to a virtual machine, provided the VM has a public IP address. NSGs control inbound and outbound traffic at the network interface or subnet level, and creating an inbound rule with source 'Internet' and destination port 80 enables HTTP access. The community discussion supports this, with high upvotes (e.g., 14 upvotes) for comments citing Microsoft documentation (e.g., Azure tutorials on NSGs) and emphasizing that NSGs are designed for such traffic filtering. While some argue that a public IP or firewall is necessary, the question's context (Azure Fundamentals AZ-900) focuses on NSG functionality without requiring assumptions about missing components. Other options (e.g., 'No') are less suitable as they overlook NSGs' core role in permitting specific traffic, which aligns with Azure best practices for basic security configurations.