observing if they lack true stems, roots, or leaves examining the plants for spores counting the number of leaves on each stalk noticing if the plants are near rocks
I gave my students this multiple choice question: A student sees many plants around a pond. The student can determine which plants are nonvascular by

Only one answer is correct among these 4 choices:
- observing if they lack true stems, roots, or leaves
- examining the plants for spores
- counting the number of leaves on each stalk
- noticing if the plants are near rocks

Could you tell me which one is correct?

observing if they lack true stems, roots, or leaves