Answer:
C. A teacher who would like to have a diversified set of investments
Explanation:
IRA stands for Individual Retirement Account. So, it's aimed for people who haven't entered retirement age. (this eliminate option B)
Average annual return for IRA is only between 7-10%. It's not the fastest method to grow your investment. (this eliminate option A.)
Traditional IRA generally tax free, but there are several exceptions made for people in high paying jobs. (Doctors are only allowed to put $7,000 in non-taxable account) (This eliminate option D)
When you put your money in an Individual Retirement Accounts, your money will be re-invested by the Custodians. The custodians will spread your investment into several sectors in order to minimize the risk of losing it during a crash. (This is why Option C is the answer)