Final answer:
The correct compound for dinitrogen monoxide is N2O; it is also commonly known as nitrous oxide.
Step-by-step explanation:
The correct compound for dinitrogen monoxide is option (a) N2O. When naming compounds, the prefixes indicate the number of each type of atom present in the compound. The prefix 'di-' corresponds to two nitrogen atoms, and 'mono-' refers to one oxygen atom. Hence, dinitrogen monoxide translates to N2O. This compound is also commonly known as nitrous oxide, which is a name you should remember along with other common names of compounds encountered in chemistry studies.