()your advice yesterday,I would have missed the train.A.Had

A Had i not taken = if i had not taken
虚拟语气：
与现在事实相反 If I (we,you,he,they)+ 动词过去式(be的过去式用were)
I(we) should.You would.He would .They would+动词原形
与过去事实相反 If I (we,you,he,they)+had+过去分词
I(we) should.You would.He would .They would +have+动词过去分词
与将来事实可能相反 If I (we,you,he,they)+ 动词过去式(be的过去式用were)/were to/should I(we) should.
You would.He would .They would +动词原形

答案选A A.Had I not taken
Had I not taken 是if i had not taken的倒装，因为后面是would，是对过去的虚拟，所以意思是如果我昨天采纳了你的建议，我就不会错过这趟火车。

Had I not taken用于“与过去相反”的虚拟语气，表示“要不是因为...”。