All of those choices are unreasonable. Why? Take it like this...
The head is obvious. You die.
The arms? Just ask anyone who's ever wanted to write a book or do anything you NEED hands for. Amplify it if it's your passion to do that thing. (For me, writing is my passion, so yeah.)
The legs? I've already had an instance in my life where I've been unable to walk, and at a young age too. It's why I don't make fun of people in wheelchairs. The concept of never walking again is unacceptable FOREVER.
The genitals... ARE YOU KIDDING ME?! If you need a reason for why that's unreasonable, you're not a man!
Sorry, but this is not a question you can ask unless you're willing to replace all the parts with cyborg equivalents or something. And good ones.