which system (MAC address) had a specific IP address at a specific time?

When investigating a network that uses DHCP to assign IP addresses, where would you look to determine which system (MAC address) had a specific IP address at a specific time?

A.
On the individual computer ARP cacheOn the individual computer ARP cache

B.
In the Web Server log files

C.
In the DHCP Server log files

D.
There is no way to determine the specific IP address