【名词&注释】
肝肾阴虚(liver-kidney yin deficiency)、脾肾阳虚(yang deficiency of spleen and kidney)、互为因果(reciprocal causation)
[单选题]补阳还五汤中重用黄芪的用意是()
A. 益气生肌 B. 补气升阳 C. 补气行血 D. 益气托毒 E. 补气行水