If \(\cos \theta =4x~and~\sin \theta =\frac{4}{x}\left( x\ne 0 \right),\)then the value of \(\left( {{x}^{2}}+\frac{1}{{{x}^{2}}} \right)\) is:

• A. 1/16
• B. 1/2
• C. 1/3
• D. 1/4