Official Solution:If \(n\) is an integer such that \(\frac{1}{9} < \frac{1}{n^2-1} < \frac{1}{2}\), what is the value of \(n\)? Given that \(n\) is an integer, for the inequality \(\frac{1}{9} < \frac{1}{n^2-1} < \frac{1}{2}\) to hold true, \(\frac{1}{n^2-1}\) must be \(\frac{1}{8}\), \(\frac{1}{7}\), \(\frac{1}{6}\), \(\frac{1}{5}\), \(\frac{1}{4}\), or \(\frac{1}{3}\). Hence, \(n^2-1\) must be 8, 7, 6, 5, 4, or 3. Consequently, \(n^2\) must be 9, 8, 7, 6, 5, or 4. However, \(n^2\) cannot be 8, 7, 6, or 5, because in these cases \(n\) won't be an integer. Therefore, \(n^2\) is either 9 or 4, making \(n\) equal to -3, 3, -2, or 2. The question essentially asks: if \(n\) is -3, 3, -2, or 2, what is the value of \(n\)?
(1) \(\frac{1}{3} > \frac{1}{1 - n} > \frac{1}{7}\).
Given that \(n\) is an integer, for the inequality \(\frac{1}{3} > \frac{1}{1 - n} > \frac{1}{7}\) to hold true, \(\frac{1}{1 - n}\) must be \(\frac{1}{4}\), \(\frac{1}{5}\), or \(\frac{1}{6}\). Hence, \(n\) is -3, -4, or -5. Since from the stem \(n\) is -3, 3, 2, or -2, then \(n\) must be -3. Sufficient.
(2) \(n\) is not an even integer.
This statement rules out \(n\) being 2 and -2. However, \(n\) can still be 3 or -3. Not sufficient.
Answer: A