Final answer:
Developing an implementation plan is not a task of systems selection; it is a subsequent step after a system has been chosen.
Step-by-step explanation:
The issue that is not a task of systems selection is D. develop an implementation plan. System selection involves evaluating potential designs relative to constraints and criteria, and then choosing the best fit for the requirements at hand. During this process, issues such as determining what software design will implement the logical specification (A), choosing acquisition financing methods (B), and determining appropriate acquisition ancillaries (C) are considered. However, developing an implementation plan is actually a subsequent step after the selection has been made, focused on the practical aspects of deploying the chosen system.