I am asked this question at least once a week by my clients. It seems like a very straight forward question that initiates a simple answer. Buy to honest, this is a very complex question that need direct attention to many different variables.
Choosing the right firearm depends on the person. The size, shape, caliber, and weight of the firearm are all important factors. The skill level and prior training of the person may also be a factor. The best way to find out what firearm works best for you is hands-on application with the weapon.
Find a certified Firearms Instructor and schedule an appointment at a gun range so you can find out if the weapon is a good fit for your needs. Ask a lot of questions and think of what-if scenarios.