Answer:
II. The discount may be accreted at the option of the bondholder
III. The discount is subject to tax
Explanation:
The discount is treated as taxable interest income earned. Regular interest earned (coupon) is not taxed by the federal government. The investor can accrete the discount annually as taxable interest income earned or can wait until he/she sells the bond or it matures to calculate accumulated "earned" discount (and pay taxes).