Answer
$ a.\quad$ False
$ b.\quad$ True
$ c.\quad$ False
$ d.\quad$ True
Work Step by Step
Apply the procedure "Finding asymptotes..." on page 336,
$a.$
$-1$ is a zero of the denominator $\Rightarrow x=-1$, but it is not a vertical asymptote. Rather it is a "hole" (removable discontinuity which cancels in the denominator).
$b.$
$2$ is a zero of the denominator $\Rightarrow x=2$ is a vertical asymptote.
$c.$ and $d.$
The degree of the numerator (2) equals the degree of the denominator.
The leading coefficient of the numerator is 1.
The leading coefficient of the denominator is 2.
By the mentioned procedure (step 2b), the horizontal asymptote is
$y=\displaystyle \frac{1}{2}$
(c) is false, (d) is true.
