I_ a lot there days as a consequence of the sudden change of the weather,so I have to see the doctor this afthernoon a.coughed b.have been coughing c.will cough d.had coughed

I_ a lot there days as a consequence of the sudden change of the weather,so I have to see the doctor this afthernoon a.coughed b.have been coughing c.will cough d.had coughed
I_ a lot there days as a consequence of the sudden change of the weather,so I have to see the doctor this afthernoon a.coughed b.have been coughing c.will cough d.had coughed

I_ a lot there days as a consequence of the sudden change of the weather,so I have to see the doctor this afthernoon a.coughed b.have been coughing c.will cough d.had coughed
选b 现在完成进行时 表从过去持续到现在或将来继续的动作.