When x< is 0,

If a & gt=0, the minimum value of f(x) is f (0) = a 2.

If a

When x> is 0,

The minimum value of f(x) is f( 1)=a+2.

From the meaning of the title, you must first have a & gt=0.

And then a 2.

The solution is-1

Together, it is

Option d