What is a significant difference between host and zone keys generated by dnssec-keygen?

What is a significant difference between host and zone keys generated by dnssec-keygen?
A . There is no difference.
B . Zone key files contain a public and private key.
C . Host keys files contain a public and private key.
D . Host keys must always be generated if DNSSEC is used; zone keys are optional
E . Zone keys must always be generated if DNSSEC is used; host keys are optional

View Answer

Answer: B