Which of the following gives a positive iodoform test? The reaction is shown below:
$2,3,5-\text{trimethylhepta-2,4-diene} \xrightarrow[(2) H_2O/Zn]{(1) O_3} X (C_3H_6O) + Y (C_3H_4O_2) + Z (C_2H_4O)$

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:

The major product $Q$ of the following reaction scheme is:

Arrange the following compounds in order of decreasing reactivity for nucleophilic addition reaction:
$(I)$ $CH_3COCH_2Cl$
$(II)$ $ClCH_2CHO$
$(III)$ $HCHO$
$(IV)$ $CH_3COCH_3$

Consider the following chemical reaction.
$CH \equiv CH \xrightarrow[{(2) CO, HCl, AlCl_3}]{{(1) Red hot Fe tube, 873 K}} \text{Product}$
The number of $sp^{2}$ hybridized carbon atom$(s)$ present in the product is ..........

The enol form of acetone,after treatment with $D_2O$,gives: