Minimum value is going to be in the y part of our coordinate, so we can just look there. I went ahead and used a graphing calculator to make things easy.
Starting off with option 2, we can see the minimum is -10. And in option 4 we can see the smallest y value is -6.
Using a graphing calculator (I used desmos), we can graph these other functions and figure out their minimums.
Option 1's y minimum is -7, and Option 3's y minimum is -2.25.
Option 1: -7
Option 2: -10
Option 3: -2.25
Option 4: -6
The questions asks for the <em>smallest</em> minimum value, which in this case is option 2.
