Answer:
When the volume of product increases.
When the weight of the product decreases.
Option (a) and (d) are correct.
Explanation:
The overall density of the product can be decreased:
a. Increase the volume of the product (and keep the material same)
d. Decrease the weight of the product ( and keep the same material ).
Density is calculated as the ratio of mass to the volume.
Density is inversely related to volume and directly related to mass.
So, when the mass of the product is increased then the density will increase keeping the material same. Density will also increase when the volume of the product decreased.