We have been given that a bank offers a four year cd with an interest rate of 2.75%. The penalty for early withdrawal from the CD is nine months of simple interest, calculated on the amount withdrawn. Rachel withdraws $2250 after one year. We are asked to find the amount of penalty.
We will use simple interest formula to solve our given problem.
, where,
I = Amount of interest,
P = Principal amount,
r = Annual interest rate in decimal form,
t = Time in years.

Since our given time is in months, so we need to convert 9 months into year.
1 year = 12 months
9 months = 
Upon substituting our given values in simple interest formula, we will get:


Upon rounding to nearest dollar, we will get:

Therefore, the penalty will be $46 and option 'a' is the correct choice.