Answer
(d)
Work Step by Step
Step 1. The leading term of the function is $-x^4$, with a coefficient of $-1$ and an even power. Thus, we can identify its end behaviors as $x\to-\infty, y\to-\infty$ and $x\to\infty, y\to-\infty$. That is, the curve falls to the left and also falls to the right.
Step 2. Based on the above result, we can match the function to graph (d).
