A package is never accepted for delivery by the delivery service unless it is within the established size limits. All packages accepted for delivery by the delivery service have a return address.
A package is never accepted for delivery by the delivery service unless it is within the established size limits.--> being within the established size limits is a necessary condition for a package to be accepted for delivery
All packages accepted for delivery by the delivery service have a return address. --> if a package is accepted for delivery(sufficient condition) then the package has a return address
If the statements above are true, which of the following must also be true?
(A) The delivery service charges more for heavier packages than for lighter packages. - incorrect, the passage does not provide us any information on the basis of which we can claim that delivery service charge increases with package weight.
(B) The delivery service will always accept for delivery a package that is within the established size limits.-incorrect, this mixes up a necessary statement and sufficient condition
(C) If a package is within the established size limits and has a return address, it will be accepted for delivery by the delivery service no matter how heavy the package is. - incorrect, there might be other factors that affect whether a package is accepted for delivery
(D) A package that is not within the established size limits but has a return address is never accepted for delivery by the delivery service. - Correct, we are already told that being within the established size limits is a necessary condition for a package to be accepted for delivery
(E) The delivery service does not charge for packages that must be returned to the sender. - incorrect
Answer D