Hello, Zorro,
From what I perceive, the purpose of your exercise is : 1) for students of Russian to remember that only the imprefective forms are used in the Present tense, while both imperfective and perfective are used in the Past and in the Present, -- and you already know it,
And 2) for you to recognize which ones are the imperfective, either by their prefizes or by their suffixes.

You are right, since the choice you are offered is between "умываться" and "умыться", then the example should have been, "я открываю глаза (which is somewhat artificial, we would say, "просыпаюсь"), встаю, УМЫВАЮСЬ....."

Possibly, neither the author of the textbook, nor the editor re attentive enough to notice a discrepancy between the task and the example. You noticed, and it means you are learning well! Congrats!