What is obtained by the oxidation of ethyl alcohol with $K_2Cr_2O_7$?

The compound which gives the most stable carbonium ion on dehydration is

Iodoform can be obtained on warming $NaOH$ and iodine with:

Major products $(C)$ and $(D)$ will be respectively:

Which of the following compounds would not react with Lucas reagent at room temperature?

The vapours of an alcohol $(X)$ are passed over $Cu$ heated at $300^{\circ} C$,where an alkene is formed as the product. The alcohol $(X)$ is expected to be $:-$