Which two conditions must be true?

You need to replicate a table from a master to a slave. The master and slave copies of the
table will have different number of columns. Which two conditions must be true?

A.
The master database cannot have more columns than the slave. Only the slave deatbase
can have more columns.

B.
Each extra column in the copy with more columns must not have a default value.

C.
Columns that are common to both versions of the table must be defined in the same
order on the master and the slave.

D.
The slave database cannot have more columns than the master. Only the master
database can have more columns.

E.
Columns that are common to both versions of the table must come first in the table
definition, before any additional columns are additional columns are defined on either
server.

Explanation: