13. One of your coworkers has recently reconfigured the firewall rule set, and users immediately began to report that they cannot receive any traffic at all from the Web. You examine the firewall rule set for issues. Which of the following could be considered a likely issue that would prevent all traffic from passing through the firewall? (A)Implicit deny (B) Explicit allow at the bottom of the rule set (C) Explicit deny at the top of the rule set (D) Implicit allow at the top of the rule set