What property of ARP causes cached IP-to-MAC mappings to remain in memory longer?

Question:
What property of ARP causes cached IP-to-MAC mappings to remain in memory longer?

• Entries in an ARP table are time-stamped and are purged after the timeout expires.
• A static IP-to-MAC address entry can be entered manually into an ARP table.
• The type field 0x806 appears in the header of the Ethernet frame.
• The port-to-MAC address table on a switch has the same entries as the ARP table on the switch.

Exam with this question: CCNA 1 v7 Modules 8 – 10 Exam Answers