Ajoin in which the joining condition is based on equality between values in the common columns is called a(n): a) equi-join. b) unilateral join. c) natural join. d) both a and c. ill take a value of contains one or more rows. if the subquery returns an intermediate results table which true false undefined the following queries produce the same results. select distinct customer_name, customer city from customer, salesman where customer. salesman-id = salesman. salesman_id and salesman. lname = 'smith' select customer_name, customer city from customer where customer. salesman id (select salesman_id from salesman where iname 'smith'); true false