Griskevicius, Et Al

Griskevicius, et al. (2010) suggested that green products may serve as costly signals. What does this mean?

A) It means these products send the message that sustainable living is a luxury only the wealthy can afford.
B) It means that these products make their owners focus on personal costs and self-sacrifice rather than on social responsibility.
C) It means that these products reinforce the idea that sacrifice is the key to sustainability.
D) It means that these products send the message that the person who uses them is willing and able to make personal sacrifices for the benefit of the greater good.