This is a basic problem.

f'(x)=2x/(x？ +4) - e^(x- 1)

When x→+∞

2x/(x？ +4)→0

e^(x- 1)→+∞

So f'(x)→-∞

So "A" kicked it out.

The difference of BCD is the state when x=0.

f(0)=ln4 - 1/e

Ln4> 1, while1/e.

It can be seen that f(0)>0

To sum up, B is correct.