Anil says he can see the moon because the moon makes its own light, just like a bulb

Why

Anil's guess is reasonable — the moon glows, and glowing things like a bulb or the sun usually make their own light. But the moon makes none of its own. It's a giant ball of rock; the sun's light falls on it and bounces off toward us, exactly the way light bounces off a mirror or a white wall. That's why the moon has phases — we see only the part the sun is lighting, and as that lit part changes, the moon seems to grow and shrink. Test: a mirror in a dark room is invisible until a torch hits it, then it shines — yet it made no light. His sister is right: the moon reflects the sun's light rather than making its own.