Class "PDO" not found 0

#0 /home/thegeeky/mentionmate.com/classes/DB_Register.php(7): DB_Connect->__construct()
#1 /home/thegeeky/mentionmate.com/classes/Register.php(17): DB_Register->__construct()
#2 /home/thegeeky/mentionmate.com/index.php(27): Register->__construct()
#3 {main}