If buyers are required to pay a $0.10 tax per bag on Hershey's kisses, the demand curve for kisses will shift

A、a.
upward by $0.10 per bag.;
B、b.
upward by $0.05 per bag.;
C、c.
downward by $0.10 per bag.;
D、d.
downward by $0.05 per bag.