单项选择题

Ms. Kate Garland, Director of Countdown Clothing
would like to invite you,
a valued customer,
to participate in our Mammoth Winter Sale,
from Thursday through Sunday, December 12-15,
when a huge 50% discount will be offered on outerwear.
There will also be 20% off on knitwear and other winter items.
All purchases made with your Countdown Clothing loyalty card
will entitle you to additional credits towards future purchases.
* Specially imported products not included
How long will the offer last

A. One day
B. Four days
C. One week
D. Two months