Which of the following hydroxy ethers gives a $+ve$ test with Tollen's reagent?

The reagent used for the dehydration of an alcohol is

An optically active alcohol of formula $C_9H_{12}O_2$ produced the following compound when refluxed with $KMnO_4$. What is the structure of $(A)$? The original compound showed these properties also:
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Na} H_2 \text{ liberated}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Br_2} \text{ no rapid reaction}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow[{cool}]{CrO_3 / H^{+}} C_9H_8O_3$

The high boiling point of ethanol $({78.2 \ ^\circ C})$ compared to dimethyl ether $({-23.6 \ ^\circ C})$,though both have the same molecular formula $C_2H_6O$,is due to

$CH_3 CH_2 OH$ $\xrightarrow{Cl_2} CH_3 CHO$ $\xrightarrow{3 Cl_2} Cl_3 CCHO$. In the above reactions,the role of $Cl_2$ in step-$1$ and step-$2$ respectively is:

On passing vapours of an organic liquid over finely divided $Cu$ at $573 \, K$,the product was an alkene. This reaction is: