First of all this is a linear function, and the basic function f(x) has now been translated to become
3f(x + 2 ) - 1
This means the basic function has been stretched by 3 units, moved two units to the right (which is x + 2) and one unit down (- 1)
The option D, describes the transformation that occured which is;
D: Vertical stretch of 3, Right 2, Down 1.