What is true about joining tables through an equijoin?（）

• A、You can join a maximum of two tables through an equijoin.
• B、You can join a maximum of two columns through an equijoin.
• C、You specify an equijoin condition in the SELECT or FROM clauses of a SELECT statement.
• D、To join two tables through an equijoin, the columns in the join condition must be primary key and foreign key columns.
• E、You can join n tables (all having single column primary keys) in a SQL statement by specifying a minimum of n-1 join conditions.