Correct Answer: Option B: <span>whether the particles do not settle for an extended period of time
Reason: Particle size in colloidal solution ranges from 1-100 nm, while that is suspension is more than 100 nm. Due to large particle size, particles in suspension settle down, upon standing for long. Thus, the best </span>criteria determine whether a heterogeneous mixture is a colloid or a suspension is to check <span>whether the particles do not settle for an extended period of time</span>