The key to answering this question is understanding that a molecule is paramagnetic when it has one or more unpaired electrons. Let's examine each option briefly:
SO2 (Sulfur dioxide): In this molecule, all electrons are paired, making it diamagnetic.
NO2 (Nitrogen dioxide): This molecule has an odd number of electrons, which results in an unpaired electron. Hence, it is paramagnetic.
SiO2 (Silicon dioxide): This compound has all electrons paired, so it is diamagnetic.
CO2 (Carbon dioxide): This molecule also has all electrons paired, rendering it diamagnetic.
Thus, the paramagnetic oxide among the given options is:
Option B:
NO2