When phenyl magnesium bromide reacts with $t-$butanol,the product would be

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

Consider the above reaction and identify the product $P :$

Which of the following is a secondary benzylic alcohol?

Identify the reagents $X, Y, Z$ for the following dehydration reactions of alcohols:
$CH_3-CH_2-OH \xrightarrow{X} CH_2=CH_2 + H_2O$
$CH_3-CH(OH)-CH_3 \xrightarrow{Y} CH_3-CH=CH_2 + H_2O$
$(CH_3)_3C-OH \xrightarrow{Z} (CH_3)_2C=CH_2 + H_2O$

An organic compound dissolved in dry benzene evolved hydrogen on treatment with sodium. It is