If a $30 Investment Is Worth $90 Today, How Long

Multiple Choice

If a $30 investment is worth $90 today, how long ago must that $30 have been invested at 6% interest computed twice a year?

A) That $30 must have been invested approximately 19.73 years ago.
B) That $30 must have been invested approximately 19.37 years ago.
C) That $30 must have been invested approximately 18.27 years ago.
D) That $30 must have been invested approximately 20.08 years ago.
E) That $30 must have been invested approximately 18.58 years ago.