Credit card a offers an introductory apr of 4.1% for the first 3 months and a standard apr of 18.5% thereafter, while credit card b offers an introductory apr of 3.7% for the first 3 months and a standard apr of 18.9% thereafter. all else being equal, which of these statements is correct? (assume all interest is compounded monthly.)

Credit card A
First 3 months:
4.1% / 360 = 0.011% x 30 = 0.34% per month for the first 3 months.
Next 9 months:
18.5% / 360 = 0.051% x 30 = 1.54% per month for the next 9 months.

Credit card B:
First 3 months
3.7% / 360 = 0.010% x 30 = 0.30% per month for the first 3 months
Next 9 months:
18.9% / 360 = 0.0525% x 30 = 1.575% per month for the next 9 months

Credit Card B is the better deal for the first 3 months.
Credit Card A is the better deal for the next 9 months.

The answer would be option 4