19. Your favorite bicycle daily rental store has just introduced a new Customer Relationship Management system and asked you, one of their most loyal members, to test it.
The implemented features are as follows:
• Anyone can rent a bicycle, but members receive a 20% discount
• However, if the return deadline is missed, the discount is no longer available
• After 15 rentals, members get a gift: a T-Shirt
Decision table describing the implemented features looks as follows:

Based ONLY on the feature description of the Customer Relationship Management system, which of the above rules describes an impossible situation?
Explanation / Rationale
a) Is not correct. A member without a missed deadline can get a discount and a gift T-Shirt after 15 bicycle rentals
b) Is not correct. A member without a missed deadline can get a discount but no gift T-Shirt until they rented a bicycle 15 times
c) Is not correct. Non-members cannot get a discount, even if they did not miss a deadline yet
d) Is correct. No discount as a non-member that has also missed a deadline, but only members can receive a gift T-Shirt. Hence, the action is not correct