**The reasoning**
A pronoun is a word that **replaces a noun** (a person, place, or thing). Instead of saying "John is reading," we say "**He** is reading."
In this sentence, **"He"** stands in for whoever we're talking about — maybe Chidi, maybe your brother, maybe the teacher. That's exactly what pronouns do: they substitute for names.
The other words have different jobs:
- "is" = verb (shows action or state)
- "reading" = verb (the action being done)
**Why the wrong options tempt you**
**B) "is"** — This connects the subject to the action, but it's a *verb* (specifically a helping/auxiliary verb), not a pronoun.
**C) "reading"** — Also a verb. It tells us the action happening, but doesn't replace any noun.
**D) "the"** — This isn't even in the sentence! If you picked this, you misread the question.
**Quick takeaway**
**Pronouns replace nouns** — words like *he, she, it, they, we, I, you* stand in for people or things. If it's not replacing a noun, it's not a pronoun!