The value of $\sin ^2 60^{\circ} \cos ^2 45^{\circ}+2 \tan ^2 60^{\circ}-{cosec}^2 30^{\circ}$ is equal to:

$\frac{17}{24}$ $\frac{19}{8}$ $-\frac{17}{24}$ $-\frac{19}{8}$

$\frac{19}{8}$

sin²60º . cos²45º + 2 tan²60º - cosec²30º = \(\frac{3}{4}\) ×  \(\frac{1}{2}\) + 2 × 3 - 4 = \(\frac{3}{8}\)  + 2 = \(\frac{19}{8}\)