原发性甲状腺功能减退症最早出现异常的是

• A.血TSH
• B.血总T<img src="https://timg.fentiku.com/24/2016/10/17/WhCT4bk2nY.png" title='WhCT4bk2nY.png' alt='WhCT4bk2nY.png'/>
• C.血游离T<img src="https://timg.fentiku.com/24/2016/10/17/RlqTiajZti.png" title='RlqTiajZti.png' alt='RlqTiajZti.png'/>
• D.血总T<img src="https://timg.fentiku.com/24/2016/10/17/kockJwy7yf.png" title='kockJwy7yf.png' alt='kockJwy7yf.png'/>
• E.血总的T<img src="https://timg.fentiku.com/24/2016/10/17/TDB3UZvCDR.png" title='TDB3UZvCDR.png' alt='TDB3UZvCDR.png'/>、T<img src="https://timg.fentiku.com/24/2016/10/17/epchi5quMX.png" title='epchi5quMX.png' alt='epchi5quMX.png'/>

正确答案：A