Describe the end behavior of the function.
a. f(x)→ ∞ as x→ ∞ and f(x)→ -∞ as x→ -∞
b. f(x)→ -∞ as x→ ∞ and f(x)→ -∞ as x→ -∞
c. f(x)→ -∞ as x→ ∞ and f(x)→ 0 as x→ -∞
d. f(x)→ ∞ as x→ ∞ and f(x)→ 0 as x→ -∞
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