The author regards the notion that heat pumps have a genuine drawback as a

A．Do not make exaggerated claims about the products you are trying to promote.
B．Focus your advertising campaign on vague analogies and veiled implications instead of on facts.
C．Do not use facts in your advertising that will strain the prospective client's ability' to believe.
D．Do not assume in your advertising that the prospective clients know even the most elementary scientific principles.

A．explain the differences in the working of a heat pump when the outdoor temperature changes
B．contrast the heating and the cooling modes of heat pumps
C．describe heat pumps, their use, and factors affecting their use
D．advocate the more widespread use of heat pumps