In methyl alcohol solution,bromine reacts with ethylene (ethene) to yield $BrCH_2CH_2OCH_3$ in addition to $1, 2-dibromoethane$ because

Which of the following is formed when propene is heated with bromine at high temperature?

The product $(A)$ of the above reaction is:

$A$ benzene derivative did not produce a white precipitate with ammoniacal silver nitrate solution (Tollens' reagent) but decolorized cold dilute alkaline $KMnO_4$ solution (Baeyer's reagent). The compound is:

Consider the following reactions. What is $A$?
| Reaction | Observation |
| :--- | :--- |
| $A \ (C_7H_{14}) \xrightarrow{\text{ozonolysis}} B + C$ | |
| $B \xrightarrow{I_2 + NaOH, \Delta} \text{yellow ppt}$ | |
| $B \xrightarrow{Ag_2O, \Delta} \text{silver mirror}$ | |
| $C \xrightarrow{I_2 + NaOH, \Delta} \text{no yellow ppt}$ | |
| $C$ $\xrightarrow{LiAlH_4} D$ $\xrightarrow{\text{anhydrous } ZnCl_2, \text{conc. } HCl} \text{white turbidity within 5 minutes}$ | |

The presence of unsaturation in organic compounds can be tested with