complex , dependent adjectival clause

[E student]

I'm stumped

How could you combine the following two sentences into a complex sentence with a dependent adjectival clause.

The boy wore a green coat. He carried his sister home.

1) The boy who wore a green coat carried his sister home.
2) The boy wore a green coat; he carried his sister home.
3) The boy wore a green coat, and he carried his sister home.

The first sentence has the adjectival clause (who), but the rest of the sentence doesn't seem punctuated properly.

Thank you for your help

[Temico]

The boy who wore a green coat, carried his sister home.

or

The boy who was wearing a green coat, carried his sister home.