Database Design Multiple Choice

According to class material, which of the following statement is true? (a) When we do an "equijoin" on two tables, the two columns used for matching attribute values between the two table do not need to have the same attribute name. (b) When we do an "equijoin" on two tables, the two columns of values compared to pick the qualifying records must have the same attribute name. (c) When we do a "theta" join on two tables, the two columns of values compared to pick the qualifying records must have the same attribute name. (d) When we do a "natural join" on two tables, the two columns of values compared to pick the qualifying records do not need to have the same attribute name. (e) None of (a) through (d) is the correct