If it was as simple as you make it then the obvious answer if B. However, you use the most extreme examples with 10% being the bonus.
I will say that I was unaware of the -101 that you can get, so I guess the correct answer is it depends. You can find a few books including Heritage, where I play, which will offer you 100% cash bonus to join. So, it now comes down to how you reach the rollover amount. If you bet more games via ML, teasers, parlays, etc. then it would be best for you to take the rollover. However, if you solely bet the spread, then unless you get an outrageous bonus it would be better to go with the -101 lines.
I will say that I was unaware of the -101 that you can get, so I guess the correct answer is it depends. You can find a few books including Heritage, where I play, which will offer you 100% cash bonus to join. So, it now comes down to how you reach the rollover amount. If you bet more games via ML, teasers, parlays, etc. then it would be best for you to take the rollover. However, if you solely bet the spread, then unless you get an outrageous bonus it would be better to go with the -101 lines.