【单选题】When a consumer finds that an item she or he bought is faulty or in some other way does not live up to the manufacturer's claim for it, the first step is to present the warranty (保单), or any other rec...
A.
complain personally to the manager
B.
threaten to take the matter to court
C.
write a firm letter of complaint to the store of purchase
D.
show some written proof of the purchase to the store