Ethyl alcohol on oxidation with $K_2Cr_2O_7$ gives

Which of the following will not produce $CH_4$ gas when reacted with $CH_3MgBr$?

But$-2-$ol is:

An organic liquid $A$ containing $C$,$H$,and $O$ has a pleasant odour with a boiling point of $78\ ^\circ C$. On boiling $A$ with conc. $H_2SO_4$,a colourless gas is produced which decolourises bromine water and alkaline $KMnO_4$. One mole of this gas also reacts with one mole of $H_2$. The organic liquid $A$ is:

Which of the following is a secondary benzylic alcohol?

Consider the following reaction sequence:
$\text{Cyclohexanol}$ $\xrightarrow{CrO_3} A$ $\xrightarrow{CH_3MgBr / H^+, H_2O} B$ $\xrightarrow{H_2SO_4, \Delta} C$ $\xrightarrow{B_2H_6, H_2O_2, OH^-} D$
Identify the final product $D$.