If cosec 39° = x, then the value of \(\frac 1 {\rm cosec^2\;51^\circ} + \sin^2 39^\circ + \tan^2 51^\circ - \frac 1 {\sin^2 51^\circ\sec^2 39^\circ}\) is:

• A. \(\sqrt {x^2 - 1}\)
• B. x2 - 1
• C. 1 - x2
• D. \(\sqrt {1 - x^2}\)