Water is a basic human need, yet not everyone has access to it. Lack of access to clean water is a global health crisis. Today, 785 million people—1 in 9—lack access to safe water. This means that these people, mostly women and children, must travel far distances to get water, instead of working or going to school or caring for their families. Helping people gain access to clean, safe water empowers them with more time for school and work and contributes to improved health for people around the world. The first two sentences of this paragraph name the key concept of this article. How do the underlined sentences help develop this key concept? (5 point)

a. These sentences give background information on the history of the global water crisis.
b. These sentences offer a possible solution for the global water crisis.
c. These sentences tell a real-life story of a person living without access to clean water.
d. These sentences give evidence to support the claim that access to clean water is a global health crisis.