The best title for this passage would be ______.

A．relies on the social welfare systems which support them
B．has much to do with the amount of support they get from others
C．depends on their ability to deal with daily worries and troubles
D．is closely related to their strength for coping with major changes in their lives

A．they are indispensable to people's social well-being
B．they awaken people's desire to exchange resources
C．they help people to cope with life in the information era
D．they can cure a range of illnesses such as heart disease, etc