单选题：BBoiler rooms are often dirty and steamy, but this one is el

B
Boiler rooms are often dirty and steamy, but this one is el.ean and cool. Fox Point is a very new47-unit living building in South Bronx, one of the city’s poorest areas. Two-thirds of the people living there are formerly (以前) homeless people, whose rent is paid by the government. The rest are low-income families. The boiler room has special equipment, which produces energy for electricity and heat. It reuses heat that would otherwise be lost to the air, reducing carbon emissions(碳排放)while also cutting costs.
Fox Point is operated by Palladia, a group that specializes in providing housing and services to needy, people. Palladia received support from Enterprise Community Partners (ECP), which helps build affordable housing by providing support to housing developers.
ECP has created national standards for healthy, environmentally (环境方面) clever and affordable homes which are called, the Green Communities Standards. These standards include water keeping, energy saving and the use of environmentally friendly building materials. Meeting the standards increases housing construction costs by 2%, which is rapidly paid back by lower running costs. Even the positioning of a window to get most daylight can help save energy.
Michael. Bloomberg, New York's mayor, plans to create 165,000 affordable housing units for500,000 New Yorkers. Almost 80% of New York City’s greenhouse-gas emissions come from buildings, and 40% of those are caused, by housing. So he recently announced that the city’s Department of Housing and Preservation and Development (DHPD) , whose duty is to develop and keep the city’s supply of affordable housing, will require all its new projects to follow ECP’s green standards.
Similar measures have been taken by other cities such as Cleveland and Denver, but New York’s DHPD is the largest city developer of affordable housing in the country.
What is the purpose of describing the boiler room in the first paragraph?
A．To explain the measures the city takes to care for poor people.
B．To suggest that affordable housing is possible in all areas.
C．To show how the environment-friendly building works.
D．To compare old and new boiler rooms.