Acquisition cost, accumulated amortization, estimated undiscounted future cash flows (FCF) and present value of FCF of a patent are $7M, $2M, 6M and $4M, respectively. Patent : A. Impaired because its book value exceeds fair value , present value of future cash flows B. Impaired because book value exceeds undiscounted future cash flows C. not impaired because its acquisition cost exceeds undiscounted future cash flows D. not impaired because undiscounted future cash exceed its book value