D&D 5E Does a character holding a missile weapon get an OA attack?

[auburn2]

The rules for AOO states you can make a melee opportunity attack when a hostile creature moves out of reach. It does not specify that you need to be holding or use a melee weapon for this attack.

So if you are holding a bow can you hit someone with it as an improvised weapon, or alternatively make an unarmed attack by kicking the enemy when he moves out of your reach?

 

[Shiroiken]

You always have unarmed attack, which doesn't even require a free hand (kick, headbutt, etc.). You could use a ranged weapon as an improvised weapon, but that could theoretically damage it (DM judgement).