Graphs of rational functions

Let $f(x)=\dfrac{14x^4+ax^2+b}{7x^4+cx^2+d}$, where $a$, $b$, $c$, and $d$ are unknown constants. **Which of the following is a possible graph of $y=f(x)$?** *Dashed lines indicate asymptotes.* [[☃ radio 1]]