Which statement correctly distinguishes the two nūns?

Three Groups of Imperfect Forms

• Both are always removed by later particles.
• The nūn in يَفْعَلُونَ is inflectional; the nūn in يَفْعَلْنَ belongs to the feminine-plural ending.
• The nūn in يَفْعَلْنَ is inflectional; the other is not.
• Neither nūn is part of a verb ending.