This class of solid materials is made up of materials that are usually soft, ductile, have low thermal conductivity and can be opaque, translucent or transparent. a. ceramics b. composites c. metals d. polymers

The Answer is option d "polymers"

Explanation:

Polymers are also categorized as plastics.Polymers are usually soft and ductile that is it can be drawn into wires.Polymers have low heat capacity or heat conductivity that is the extent to which a polymer acts as an insulator towards the temperature.Polymers can be opaque ( not be seen through), translucent or transparent (to be seen clearly through).Hence the right answer is option d "polymers".