Which of the following compounds gives the most stable carbonium ion during dehydration?

The reaction sequence is given as:
$1-methylcyclohexene$ $\xrightarrow[alkaline \ KMnO_4]{cold} A$ $\xrightarrow[AcOH]{CrO_3} B$
Identify $A$ and $B$.

An organic compound $(A)$ reacts with sodium metal to form $(B)$. When $(A)$ is heated with concentrated $H_2SO_4$,it forms diethyl ether. What are $(A)$ and $(B)$ respectively?

$PhMgBr + (CH_3)_2CH-OH \to A$. Identify the product $A$.

$C_2H_5OH + 4I_2 + 3Na_2CO_3 \longrightarrow X + HCOONa + 5NaI + 3CO_2 + 2H_2O$
In the above reaction,'$X$' is

Glycerol on treatment with oxalic acid at $110 \ ^oC$ forms