Selection of the recommended plan is the last step in the planning process. Please see Chapter 11 in the Planning Manual, pages 218-225.
One of the alternatives that is always considered in project planning is the no-action alternative. Under the assumption that Federal agencies "should do good and not do bad" (paraphrased from Ken Orth, South Pacific Division), each action should be examined to assure that it is preferable to not doing anything. This thinking is valid in natural resources management as well as in planning.