A cylindrical tube, open at both ends, has a fundamental frequency \[{{f}_{0}}\] in air. The tube is dipped vertically into water such that half of its length is inside water. The fundamental frequency of the air column now is [RPET 1999; RPMT 1998, 2000; J & K CET 2000; KCET 2002; BHU 2002; BCECE 2003]

• A.            \[3{{f}_{0}}/4\]                   
• B.            \[{{f}_{0}}\]
• C.            \[{{f}_{0}}/2\]                      
• D.            \[2{{f}_{0}}\]