Need Help in the following multiple choice select the correct

Erin O'Brien, Director of Consumer Credit with Auckland First Bank (AFB), has implemented a "fast feedback' to keep her informed of the default rate on personal loans at the AFB member banks. On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample contained 30 defaulted loans. The 95% confidence interval for the population proportion is Select one: O a. 0.028 to 0.060 O b. 0.043 to 0.077 O c. 0.046 to 0.074 O d. 0.039 to 0.081