Which of the following is not the product of an intramolecular aldol condensation?

The formation of cyanohydrin from a ketone is an example of

The increasing order of the reactivity of the following compounds in nucleophilic addition reaction is:
Propanal,Benzaldehyde,Propanone,Butanone

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : $Image-I$ can be easily reduced using $Zn-Hg / HCl$ to $Image-II$.
Reason $R : Zn-Hg / HCl$ is used to reduce carbonyl group to $-CH_2-$ group.
In the light of the above statements,choose the correct answer from the options given below:

$P$ is an optically active compound with molecular formula $C_6H_{12}O$. When $P$ is treated with $2,4-$dinitrophenylhydrazine,it gives a positive test. However,in the presence of Tollens reagent,$P$ gives a negative test. Predict the structure of $P$.

The main reduction product of the following compound with $NaBH_4$ in methanol is