Which of the following is the best reagent to convert cyclohexanol to cyclohexene ?

The major product of the following reaction is:

Consider the following reactions:
$\left(\mathrm{a}\right)$ ${\left(\mathrm{C}{\mathrm{H}}_3\right)}_3\mathrm{C}\mathrm{C}\mathrm{H}\left(\mathrm{O}\mathrm{H}\right)\mathrm{C}{\mathrm{H}}_3\stackrel{\mathrm{c}\mathrm{o}\mathrm{n}\mathrm{c}.{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4}{\to }$
$\left(\mathrm{b}\right)$ ${\left(\mathrm{C}{\mathrm{H}}_3\right)}_2\mathrm{C}\mathrm{H}\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right)\mathrm{C}{\mathrm{H}}_3\stackrel{\mathrm{a}\mathrm{l}\mathrm{c}.\mathrm{K}\mathrm{O}\mathrm{H}}{\to }$
$\left(\mathrm{c}\right)$ ${\left(\mathrm{C}{\mathrm{H}}_3\right)}_2\mathrm{C}\mathrm{H}\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right)\mathrm{C}{\mathrm{H}}_3\stackrel{{\left(\mathrm{C}{\mathrm{H}}_3\right)}_3{\mathrm{O}}^{\ominus }{\mathrm{K}}^{\oplus }}{\to }$
$\left(\mathrm{d}\right)$

Which of the reaction(s) will not produce Saytzeff product?

Identify the main product in the reaction

$\mathrm{C}{\left({\mathrm{CH}}_3\right)}_3\mathrm{OH}\frac{20\%{\mathrm{H}}_3{\mathrm{PO}}_4}{358 \mathrm{K}}\to$?

The reagent ${}^{\text{'}}\mathrm{X}^{\text{'}}$ used for the following reaction is

The major product $\left[\mathrm{R}\right]$ in the following sequence of reaction is :

The product "$\mathrm{A}$" and "$\mathrm{B}$" formed in above reactions are