An open pipe is in resonance in 2nd harmonic with frequency \[{{f}_{1}}\] Now one end of the tube is closed and frequency is increased to \[{{f}_{2}}\] such that the resonance again occurs in nth harmonic. Choose the correct option

• A. \[n=3,\,{{f}_{2}}=\frac{3}{4}{{f}_{1}}\]
• B. \[n=3,\,{{f}_{2}}=\frac{5}{4}{{f}_{1}}\]
• C. \[n=5,\,{{f}_{2}}=\frac{3}{4}{{f}_{1}}\]
• D. \[n=5,\,{{f}_{2}}=\frac{5}{4}{{f}_{1}}\]