What files does the last command read to determine login history?

A.
/var/adm/wtmp

B.
/var/adm/utmpx

C.
/var/adm/wtmpx

D.
/var/adm/lastlog

Explanation:

The utmpx file contains user access and administration information. The file wtmpx contains the history of user access and administrative information.
To read the contents of the wtmpx file you have to use the fwtmp command: cat /var/adm/wtmpx | /usr/lib/acct/fwtmp | more