In the marketing context, what does $80$:$20$ mean?

a$.80\%$ of a marketplace is segmented, while $20\%$ is untapped.

b$.80\%$ of a company's sales come from $20\%$ of its customers.

c$.80\%$ of niche marketers give primary importance to the price of a product, while $20\%$ give importance to their customers.

d$.80\%$ of a company's customers give $20\%$ importance to the product design.