已知函数y=f（x）的图象与函数y=2^x+1（x＞0）的图象关于直线y=x对称，则（　　）

A．f（x）=log₂x-1（x＞2）

B．f（x）=log₂x-1（x＞0）

C．f（x）=log₂（x-1）（x＞2）

D．f（x）=log₂（x-1）（x＞0）

Which of the following is not one of the responsibilities of the Tariff Commission（）

A. To formulate the guideline for drawing up the regulations.

B. To set temporary tariff rates.

C. To levy Customs tariffs on imports & exports.

D. To examine the draft of the amendment to tarif