Since you're paying 5% more than par value for the bond, you might expect the yield to be the nominal yield (7.5%) divided by that premium:
... 7.5% / 1.05 = 7.14%
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However, the internal rate of return for an outlay of 1050 and an income stream of 75×6 with 1000 added to the last coupon is 6.47%.
We believe the correct choice is not among those offered.