Which sentence uses periods correctly?

Amrs. mj chong went to the meeting at 4:00 pm.
Bmrs. m.j. chong went to the meeting at 4:00 p.m.
Cmrs m.j. chong went to the meeting at 4:00 p.m..
Dmrs mj. chong went to the meeting at 4:00 p.m.?