The correct option is B Moulds
Minute living organisms dispersed in atmosphere are known as viable particulates. Bacteria, fungi, moulds, algae are the examples of variable particulates.
Non-viable Particulates:
They are formed either by the breakdown of large materials or by the condensation of minutes particles and droplets.
Examples include : Fumes, smoke, mist, dust
Correct options are (a) and (b)