A 10-cent-per-box tax on producers of cigars will

a. shift the firm's ATC and MC curves upward by the full amount of the tax.
b. induce the firm to produce less but will not shift the firm's MC curve.
c. shift the firm's ATC and MC curves downward by the full amount of the tax.
d. shift the MC curve upward but will not cause any shift in the ATC curve.

A