The disappearance of the characteristic purple colour of $KMnO_4$ in its reaction with an alkene is the test for unsaturation. It is known as

Identify $C$ in the following series $C_3H_7I$ $\xrightarrow[alc.]{KOH} A$ $\xrightarrow[\Delta]{NBS} B$ $\xrightarrow[alc.]{KCN} C$.

The major product of the following reaction is:

The major product of the reaction is:

Ozonolysis of an alkene with molecular formula $C_9H_{18}$ yields $2, 2-$ dimethylpropanal and $2-$ butanone. The alkene is ....................

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Cis form of alkene is found to be more polar than the trans form.
Reason $(R)$: Dipole moment of trans isomer of $2$-butene is zero.
In the light of the above statements,choose the correct answer from the options given below: