A sign in a department store reads: 'Summer Sale! Get 30% off all marked items. This offer is valid until August 31st and applies only to purchases made with our store loyalty card. Excludes new arrivals and designer brands.'
Based on the sign, which condition must be met to get 30% off?
A) The purchase must be made in September.
B) The customer must buy a new arrival.
C) The customer must use a store loyalty card.
D) The discount applies to designer brands.
E) All items in the store are included in the sale.