Which of the following reagents will convert a carboxylic acid into an ester?

$CH_2=CH-CO-OCH_3$ (methyl acrylate,bp $81^\circ C$) + $CH_3-CH_2-CH_2-CH_2-OH$ (n-butyl alcohol,bp $117^\circ C$) $\xrightarrow{TsOH, \Delta} (A)$ (bp $145^\circ C$) + $CH_3OH$ (bp $65^\circ C$). Product $(A)$ of the above reaction is:

The dehydration of malonic acid $CH_2(COOH)_2$ with $P_4O_{10}$ gives:

The major product of the following reaction is:

Heating a mixture of ethyl alcohol and acetic acid in the presence of conc. $H_2SO_4$ produces a fruity-smelling compound. This reaction is called:

Which of the following compounds reacts with methyl magnesium iodide to produce ethyl acetate?