In series LCR circuit voltage drop across resistance is 8V, across inductor is 6V and across capacitor is 12V. then

Since $\cos \theta =\frac{R}{Z}=\frac{IR}{IZ}=\frac{8}{10}=\frac{4}{5}$

(also, $\cos \theta$ can never be greater than 1)

Hence (c) is wrong.

Also $I{X}_C>I{X}_L\Rightarrow X_C>X_L$

Current will be leading.

In an LCR circuit,

$v=\sqrt{{\left(v_L-v_C\right)}^2+v_R{}^2}=\sqrt{{\left(6-12\right)}^2+8^2}$

V=10; which is less than voltage drop across capacitor.