Acetone reacts with iodine to form iodoform in the presence of

Give the reactivity order towards $HCN$ for the following compounds:
$(I)$ $Ph-CO-CH_3$
$(II)$ $CH_3-CO-CH_3$
$(III)$ $CH_3-CHO$
$(IV)$ $Ph-CO-CH_2-CH_3$

Assertion : Benzaldehyde is more reactive than ethanol towards nucleophilic attack.
Reason : The overall effect of $-I$ and $+R$ effect of phenyl group decreases the electron density on the carbon atom of $>C=O$ group in benzaldehyde.

An alkene $(A)$ $C_{16}H_{16}$ on ozonolysis gives only one product $(B)$ $C_8H_8O$. $(B)$ can also be obtained by the hydrolysis of the product obtained from the reaction between cyanobenzene and $CH_3MgBr$. $(A)$ shows geometrical isomerism and decolourises $Br_2$ water. $(B)$ on treatment with $SeO_2$ produces $(C)$. Which statement is not correct about $(B)$?

Clemmensen's reduction will convert cyclohexanone into

For the sequence of reactions,$A$ $\xrightarrow[{ether}]{{C_2H_5MgI}} B$ $\xrightarrow{{H_2O/H^{+}}}$ tert-Pentyl alcohol. The compound $A$ in the sequence is