Which of the following reagents cannot be used for the experimental reduction of a functional group?

An alkene $A$ (molecular formula $C_{5}H_{10}$) on ozonolysis gives a mixture of two compounds $B$ and $C$. Compound $B$ gives a positive Fehling's test and also forms iodoform on treatment with $I_{2}$ and $NaOH$. Compound $C$ does not give Fehling's test but forms iodoform. Identify the compounds $A, B$ and $C$. Write the reaction for ozonolysis and the formation of iodoform from $B$ and $C$.

Propene,when heated with chlorine at approximately $500^\circ C$,forms:

What is the product formed when ethylene reacts with $1\%$ cold alkaline $KMnO_4$?

What will be the product $B$ formed in the following reaction sequence?
$CH_3CH_2CH_2OH$ $\xrightarrow{PCl_5} A$ $\xrightarrow{alc. KOH} B$

Product $(A)$ is