A.Bob has max_user_connections set to zero, which blocks all his connections
B.Joe has exceeded the max_user_connections global limit
C.All users are blocked because max_user_connections is accumulated over the host account information
D.Kay is already connected elsewhere and attempting to log in again
E.Connect_timeout is too small to allow a connection to occur

A.Convert the column to TEXT and add a fulltext index to the table
B.Create multiple prefix indexes of differing lengths
C.Convert their column to BINARY
D.Redesign the table so that the most commonly searched for string patterns are in their own columns