$CH_3-C(OH)(CH_3)-CH_3 \xrightarrow[cool]{Na_2Cr_2O_7} (P)$; Product $(P)$ in the reaction is

Compound $A$ of molecular formula $C_4H_{10}O$ on treatment with Lucas reagent at room temperature gives compound $B$. When compound $B$ is heated with alcoholic $KOH$,it gives isobutene. Compound $A$ and $B$ are respectively:

Order of boiling points of the given compounds is:
$(a)$ $\text{pentan-1-ol}$
$(b)$ $\text{butan-1-ol}$
$(c)$ $\text{butan-2-ol}$
$(d)$ $\text{propan-1-ol}$

The boiling point of methanol $(CH_3OH)$ is higher than that of methyl thiol $(CH_3SH)$ because:

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A$: Alcohols react both as nucleophiles and electrophiles.
Reason $R$: Alcohols react with active metals such as sodium,potassium and aluminum to yield corresponding alkoxides and liberate hydrogen.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following gives a ketone on oxidation?