\(\mathop {\lim }\limits_{x \to  - \infty } \frac{...

Câu hỏi: \(\mathop {\lim }\limits_{x \to  - \infty } \frac{{3x + \sqrt {{x^2} + 1} }}{{2\left| x \right| + 1}}\) bằng

A. 1

B. 2

C. - 2

D. - 1