We will evaluate each statement to find the value of \(x\) and check if we can conclude a unique answer.
Statement I:
\[
2^2 + 5x + 6 = 0 \quad \Rightarrow \quad 4 + 5x + 6 = 0 \quad \Rightarrow \quad 5x + 10 = 0 \quad \Rightarrow \quad 5x = -10 \quad \Rightarrow \quad x = -2
\]
Statement II:
\[
2^2 + 7x + 12 = 0 \quad \Rightarrow \quad 4 + 7x + 12 = 0 \quad \Rightarrow \quad 7x + 16 = 0 \quad \Rightarrow \quad 7x = -16 \quad \Rightarrow \quad x = -\frac{16}{7}
\]
The two statements provide different values for \(x\):
- From Statement I, \(x = -2\)
- From Statement II, \(x = -\frac{16}{7}\)
Since each statement gives a different value for \(x\), neither statement alone can be considered sufficient to determine a unique value for \(x\). Therefore, both statements together do not provide one definitive solution.
Thus, the correct answer is:
\[
\boxed{(D) Neither statement is sufficient}
\]