What is the valuation method used for available-for-sale securities and held-to-maturity securities under GAAP?
a. Available-for-sale securities are carried at amortized cost; held-to-maturity securities are carried at market value.
b. Available-for-sale securities are carried at market value; held-to-maturity securities are carried at amortized cost.
c. Both available-for-sale and held-to-maturity securities are carried at market value.
d. Both available-for-sale and held-to-maturity securities are carried at amortized cost.