Integrate : $ \int e^x (a e^x+b)^n. dx$

Question

\[\begin {array} {1 1} (a)\;\frac{1}{a} \bigg[\frac{(ae^x+b)^n+1}{n+1}\bigg] \\ (b)\;\bigg[\frac{(ae^x+b)^n+1}{n+1}\bigg] \\ (c)\;\bigg[\frac{(ae^x+b)+1}{a(n+1)}\bigg] \\ (d)\;None \end {array}\]