The appropriate response to the question regarding the trade-off the business must make when changing its production from 20 tables and 10 benches to 15 tables and 15 benches is:
the difference between the profit of 20 tables and the profit of 15 tables.
This choice highlights the trade-off in terms of the opportunity cost of producing fewer tables in order to produce more benches, which reflects the change in profit as a result of this production shift.