Consider the operators, $\hat{a}_+ = \frac{1}{\sqrt{2}}(\hat{x} + i\hat{p}_x)$ and $\hat{a}_- = \frac{1}{\sqrt{2}}(\hat{x} - i\hat{p}_x)$, where $\hat{x}$ and $\hat{p}_x$ are the position and linear momentum operators, respectively. The commutator, $[\hat{a}_+, \hat{a}_-]$ is equal to
(a)$i\hbar$
(b)$-i\hbar$
(c)$\hbar$
(d)$-\hbar$
Answer
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