the post tax return in first is 7.5% which is lower as compared to 8% in second option. but if your effective tax rate is 15%; then first option offers returns higher.
return 10% p.a. 8% p.a.
scenario-1- 25% tax 7.5% p.a. 8% p.a.
scenario-2-15% tax 8.5% p.a. 8% p.a.
the key point is while looking at the return of any instrument you must look into post tax return of the instrument in terms of instrument and your tax bracket. 