Additives that promote the flocculation (aggregation) of suspended particles are typically which of the following?

Introduction / Context:
Flocculation combines fine particles into larger aggregates that settle or filter more readily. It is widely used in water treatment and mineral processing.

Concept / Approach:
Electrolytes compress the electrical double layer and reduce repulsive forces (DLVO theory), enabling van der Waals attraction and bridging by polymers. Certain surfactants modify surface energies and can induce hydrophobic interactions that promote aggregation. Commercial flocculants are often polyelectrolytes (anionic/cationic) that act via charge neutralization and polymer bridging.

Final Answer:
Both (a) and (b)