How do ignore and None actions in the Main Rulebase differ?

How do ignore and None actions in the Main Rulebase differ?

A.
None actions cause IDP NOT to perform any Attack Matching on this rule.

B.
Ignore actions cause IDP NOT to perform any Attack Matching on this rule.

C.
Ignore actions cause IDP to ignore and subsequently drop all traffic matching this rule.

D.
Ignore actions will cause IDP to disregard and further attack matching when an attack object is
matched.

Explanation: