Which of the following on reaction with conc. $NaOH$ gives an alcohol?

Which of the following aldehydes gives a red precipitate with Fehling solution?

Self-condensation of two moles of ethyl acetate in the presence of sodium ethoxide yields:

$X \underset{\text{Reductive}}{\stackrel{\text{Ozonolysis}}{\longrightarrow}} Y + Z$. $Y$ can be obtained by Etard's reaction,$Z$ undergoes disproportionation reaction with concentrated alkali. $X$ could be:

The given reaction
$C_6H_5-CHO + Br-CH_2-COOC_2H_5 \xrightarrow[(ii) HOH/NH_4Cl, (iii) \Delta]{(i) Zn} C_6H_5-CH=CH-COOC_2H_5$
is known as:

Which is the major product obtained by hydrolysis of the compound formed by the reaction between formaldehyde and ethyl magnesium bromide?