Select the correct advantages typically associated with centrifugal pumps in water-supply installations.

Introduction / Context:
Centrifugal pumps are the workhorse of water and wastewater systems. Their hydraulic characteristics and mechanical simplicity make them the preferred option for most municipal applications. Recognizing their typical advantages is critical in preliminary selection and design.

Given Data / Assumptions:

• Suction-lift or flooded-suction configurations.
• Continuous-duty municipal service.
• Comparison against reciprocating/positive-displacement pumps.

Concept / Approach:
Centrifugal pumps impart energy by a rotating impeller, yielding smooth flow with minimal pulsation. Their construction is relatively simple, enabling compact installations and lower purchase costs for comparable capacities. They are easily controlled via speed variation and throttling within efficiency limits.

Step-by-Step Solution:

Verification / Alternative check:
Pump catalogs and life-cycle cost analyses show why centrifugal pumps dominate municipal waterworks for medium-to-high flows at moderate heads.

Why Other Options Are Wrong:
Each of a–c is true; the comprehensive correct selection is “all the above”.

Common Pitfalls:
Ignoring limitations at very high heads or very low flows where PD pumps may be superior; assuming throttling is always efficient without considering curves.

Final Answer:
all the above.