14. Person A has six coupons to claim free ice cream cones at a dessert shop. A decides to use one coupon every 10 days until all six coupons are used. It is known that the dessert shop is closed on Sundays, and A circles the dates on the calendar when the coupons will be used, finding out that none of the dates fall on a Sunday. Then, the first time A uses a coupon is on a ( ).
(A) Monday
(B) Tuesday
(C) Wednesday
(D) Thursday
(E) Friday
14. C.

Let the day of the week when Jia first uses the coupon be $x (x \in\{0,1, \cdots, 6\})$, where $x=0$ represents Sunday, $x=1$ represents Monday, and so on.
Then the days of the week when the coupons are used are
$$
x+10 n \equiv x+3 n(\bmod 7)(n=0,1, \cdots, 5) \text {. }
$$

Thus, the six coupons will be used on the days $x 、 x+3$ 、 $x-1 、 x+2 、 x-2 、 x+1(\bmod 7)$, which indicates that none of these six days are $0(\bmod 7)$. Therefore,
$$
x \notin\{0,4,1,5,2,6\} \Rightarrow x=3 \text {. }
$$

Hence, Jia first uses the coupon on a Wednesday.