1. Determine the maximum contribution that can be made to a Keogh plan in each of the following cases. In all instances, the individual is self-employed, and the self-employment tax reduction has already been taken.

A. Self-employment income of $47,000.

B. Self-employment income of $47,000 and wage income of $30,500.

C. Self-employment income of $110,000.

D. Self-employment income of $281,000.