Assume that we have two tables SALES_TRANSACTION, CUSTOMER with the following structures and data: NOTE: Data in tables may be different from question to question. Table SALES_TRANSACTION Tahla rIISTOMER. What is returned by this SQL statement below? SELECT count(customer_zip) FROM customers; 2 3 0 4 Assume that we have two tables REGION, STORE with the following structures and data: Table REGION: Table STORE: What are the column headings in the RESULT returned by the SQL statement below? SELECT store_id "Store ID", store_name "Store Name" FROM store WHERE store_zip = '19122' UNION SELECT store_id, store_name FROM store WHERE store_zip = '10023'; STORE_ID, STORE_NAME Store ID, Store name Store ID, Store Name, STORE_ID, STORE_NAME Assume that we have two tables REGION, STORE with the following structures and data: Table REGION: Table STORE: Which store(s) is(are) returned by the SQL statement below? SELECT store_id, store_name FROM store WHERE store_zip = '19122' UNION SELECT store_id, store_name FROM store WHERE store_zip = '10023'; S2 S1,S2,S3 S1,S3 none Assume that we have two tables REGION, STORE with the following structures and data: Table REGION: Tahle STORF: Which is equivalent to the SQL statement below? SELECT store_id "Store ID", region_name "Region Name" FROM store JOIN region USING (region_id); SELECT s.store_id "Store ID", r.region_name "Region Name" FROM store s RIGHT JOIN region r ON s.region_id = r.region_id; SELECT s.store_id "Store ID", r.region_name "Region Name" FROM store s NATURALJOIN region r ON s.region_id = r.region_id; SELECT s.store_id "Store ID", r.region_name "Region Name" FROM store s JOIN region r ON s.region_id = r.region_id; SELECT store_id "Store ID", region_name "Region Name" FROM store JOIN region ON region_id = region_id