Which of the following statements regarding the reduction of Social Security retirement benefits is$($are$)$ correct?

I. Besides early retirement, there are $2$ other situations in which beneficiaries can have their benefits reduced: through the retirement earnings limitations test and through taxation of benefits.

II$.$ A person can continue to work even if he is receiving Social Security retirement benefits, but benefits may be reduced if the worker has not reached full retirement age and earnings exceed certain limitations$.$