Alice Buys a Home Theater System from Blastaphonic Audio and Video,paying

Alice buys a home theater system from Blastaphonic Audio and Video,paying cash.Alice was aware that Fourth National Bank had a perfected security interest in all the inventory of Blastaphonic.Which of the following statements is true?

A) The home theater system is not subject to a security interest once Alice purchases it.
B) The home theater system remains subject to the security interest of Fourth National Bank because Alice had actual knowledge of the security interest.
C) The home theater system is not subject to a security interest once Alice purchases it so long as the remaining inventory of Blastaphonic is adequate to secure the amount of the indebtedness.
D) The home theater system remains subject to the security interest of Fourth National Bank,and this would be true even if Alice was not aware of Fourth National Bank's security interest.