14. Consider a uniform tubes open at both end, which is called the open tube. Suppose an open tube A with a length L has a fundamental frequency f0. If one-third of A's length is cut off, resulting in open tube B, what is the fundamental frequency ? If the open tube B is then connected to another open pipe with one-third of B's length, forming open pipe C, what is the fundamental frequency ? (A) (B) (C)(D)