Choice "A" is correct. Debt securities (bonds) classified as held-to-maturity are reported at amortized cost (that is, cost adjusted for amortization of premium or discount; approaches face value). Debt securities classified as available-for-sale are reported at fair value.
Choice "c" is incorrect. While amortized cost is the appropriate treatment for debt securities classified as held-to-maturity, this is not the correct treatment for securities classified as available-for-sale.
Choice "d" is incorrect. Fair value is not the appropriate treatment for debt securities classified as held-to-maturity.
Choice "b" is incorrect. Fair value is not the appropriate treatment for debt securities classified as held-to-maturity. Nor is amortized cost the appropriate treatment for debt securities classified as available-for-sale.