A compound (A) ${\mathrm{C}}_5{\mathrm{H}}_{10}\mathrm{O}$ forms a phenyl hydrazone and gives negative Tollen's and positive iodoform test compound can be:

The suitable reagent of the following reaction is:

$\mathrm{A}$ will:

Predict the product of following aldol condensation reaction:

${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CHO}\stackrel{{\mathrm{OH}}^{-}/\mathrm{\Delta }}{\to }$

Predict the product of following aldol condensation reaction:

$\mathrm{Ph}-{\mathrm{CH}}_2-\mathrm{CHO}\stackrel{{\mathrm{OH}}^{-}/\mathrm{\Delta }}{\to }$

Predict the product of following aldol condensation reaction:

$\mathrm{Ph}-\mathrm{CO}-{\mathrm{CH}}_3\stackrel{{\mathrm{OH}}^{-}/\mathrm{\Delta }}{⟶}$

Indicate the starting aldehyde or ketone from which, the following compound is formed by an aldol condensation reaction:

$2-$Ethyl$-3-$hydroxy hexanal