Q: What internal hard drive is compatible with Macbook Pro (13-inch, Mid 2012)?

I live in India. I have a MacBook Pro (13-inch, Mid 2012). My Macbook crashed 3 days ago. Apple said the internal hard disk needed replacement. They gave me two options.

1. They get a new hard drive replaced from Apple for 12000 INR (280$),

or 2. If you find it expensive, you can buy an internal hard disk from sources other than Apple and we will fix it in for you.

I have decided to go with option 2, because option 1. is not feasible for me!

Now my question is,

What type of internal hard disk should I buy?

or

What are the specifications for the internal hard drive that must be met to suit my MBP?

Getting my internal hard disk replaced is something I've never done before.

I have a MBP, (13-inch, Mid 2012 model)