Which would require a Layer 7 Firewall?

Which would require a Layer 7 Firewall?
A. block a specific port
B. block a subnet range
C. block a host
D. block a specific application

Correct Answer: D
Explanation/Reference: Explanation:

Reference: https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.1/administration/GUID-8F3CB282-B38E-49E1-951A-7D6B972B1FB7.html