The treatment of galena with ${\mathrm{HNO}}_3$ produces a gas that is

Concentrated nitric acid is a strong oxidising agent and attacks most metals except noble metals such as gold and platinum. The products of oxidation depend upon the concentration of the acid, temperature and the nature of the material undergoing oxidation.

$\mathrm{PbS}+\mathrm{dil}.{\mathrm{HNO}}_3\to \mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2+\mathrm{S}+\mathrm{NO}+{\mathrm{H}}_2\mathrm{O}$

$\mathrm{NO}$ is paramagnetic due to the presence of unpaired electron. It is a neutral oxide. It is colourless.

Hence, $\left(\mathrm{A}\right)$ and $\left(\mathrm{D}\right)$ are correct statements.