Understanding and application

What is the grammatical role of هُوَ in فَهُوَ مِنْهُمْ?

Humility, Gratitude, Goodwill, and Conditional Sentences (Hadith 188–198)

• A past-tense verb
• Subject of a nominal clause whose predicate is مِنْهُمْ
• A preposition
• A sound feminine plural