in both relation comp_id is common attribute se we can take natural join but we have to check left outer join and right outer join .in company relation the element of attribute comp_id is (15,16,17,18,19) and in food relation the element of comp_id is (15,16,17,18,19,20) for left outer join all the element of comp_id of first relation will be present and there will be matching with the other joined relation if it does not match then null will be assign.so according to this option (A) is correct but there is miss print for item no. 3 and 7 which is already commented.