When acetaldehyde is reacted with $LiAlH_4$,what is the product formed?

$CH_3CH=CHCHO$ $\xrightarrow[\text{Aldol condensation}]{OH^{-}}$ $\xrightarrow{\Delta} A$; Product $A$ is

Which of the following statements is $NOT$ false for benzaldehyde?

$A$ reaction of benzonitrile with one equivalent of $CH_{3}MgBr$ followed by hydrolysis produces a yellow liquid $P$. The compound $P$ will give a positive result for which of the following tests?

In which of the following reactions,two products will be formed other than triphenylphosphine oxide $(Ph_3PO)$?

Cyclohexylamine when treated with nitrous acid yields $(P)$. On treating $(P)$ with $PCC$ results in $(Q)$. When $(Q)$ is heated with dilute $NaOH$,we get $(R)$. The final product $(R)$ is: