By default, which access rule is applied inbound to the inside interface?

A.
All IP traffic is denied.

B.
All IP traffic is permitted.

C.
All IP traffic sourced from any source to any less secure network destinations is permitted.

D.
All IP traffic sourced from any source to any more secure network destinations is permitted

Explanation:
http://www.cisco.com/en/US/docs/security/asa/asa84/configuration/guide/access_rules.html#wp10
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Implicit Permits
For routed mode, the following types of traffic are allowed through by default:
•IPv4 traffic from a higher security interface to a lower security interface.
•IPv6 traffic from a higher security interface to a lower security interface.
Note These defaults might not be true if you have configured a global access rule.
For transparent mode, the following types of traffic are allowed through by default:
•IPv4 traffic from a higher security interface to a lower security interface.
•IPv6 traffic from a higher security interface to a lower security interface.
•ARPs in both directions