Which Description Is the BEST Example of a Market Niche

Which description is the BEST example of a market niche?

A) all the potential customers who are interested in buying a new vehicle
B) the four deli sandwich shops that serve customers in and near a college campus
C) elderly people, residing in assisted living centers, who suffer from macular degeneration
D) people interested in taking a cruise to any of the Caribbean islands
E) selecting to advertise women's apparel in magazines rather than through television ads