It was with great joy _____ we received the news that the oil prices had been reduced. [ ]

A. that

B. which

C. since

D. because

下列哪项是肾脏合成分泌的激素()

A．肾素

B．前列腺素

C．1-α羟化酶

D．醛固酮

E．促红细胞生成素