Final answer:
To find the interest rate, use the simple interest formula with the principal, total amount, and time period to calculate that the annual interest rate of Giselle's account is 6%, which is option B.
Step-by-step explanation:
To calculate the interest rate of Giselle's savings account, we use the formula for simple interest: I = Prt, where I is the interest, P is the principal amount, r is the interest rate, and t is the time in years. Giselle's principal amount P is $10,000, the total amount in the account after 8 years is $14,800, and the interest I is the difference between these two amounts, which is $14,800 - $10,000 = $4,800. Given that the time t is 8 years, we can rearrange the formula to solve for the interest rate r.
We have
$$4800 = $10000 \times r \times 8$$
$$4800 = $80000r$$
$$r = \frac{4800}{80000}$$
$$r = 0.06$$
Therefore, the interest rate is 6%, which corresponds to option B.