Choose the term described by the sentence： Large-scale public services, such as water and power supplies, road, rail and radio communications, etc. needed to support economic activity, esp. industry, trade and commerce. ( )

Choose the term described by the sentence： Large-scale public services, such as water and power supplies, road, rail and radio communications, etc. needed to support economic activity, esp. industry, trade and commerce. ( )
A.infrastructures
B.investment
C.expertise
D.foundation
正确答案：infrastructures