Read the following paragraphs and answer the question.
①Since we are social beings, the quality of our lives depends in large measure on our interpersonal relationships. One strength of the human conditions is our possibility to give and receive support from one another under stressful(有压力的) conditions. Social support makes up of the exchange of resources among people based on their interpersonal（人际间的） ties. Those of us with strong support systems appear better able to deal with major life changes and daily problems. People with strong social ties live longer and have better health than those without such ties. Studies over types of illnesses, from depression (抑郁症) to heart disease, show that the presence of social support helps people defend themselves against illness, and the absence of such support makes poor health more likely.
②Social support cushions stress in a number of ways. First, friends, relatives and co-workers may let us know that they value us. Our self-respect is strengthened when we feel accepted by others in spite of (尽管) our faults and difficulties. Second, other people often provide us with informational support. They help us to define and understand our problems and find solutions to them. Third, we typically find social companionship ( 同伴) supportive. Taking part in free-time activities with others helps us to meet our social needs while at the same time distracting(转移注意力) us from our worries and troubles. Finally, other people may give us instrumental (手段的) support—money aid, material resources, and needed services—that reduces stress by helping us resolve and deal with our problems.
What is the subject discussed in the text?（）
A.正确答案AInterpersonal relationship
B.Kinds of social support
C.Ways to deal with stress
D.Effects of stressful conditions
