
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Evaluate the expression $3^{-k} - 3^{-(k+2)} + 3^{-(k+1)} - 3^{-(k-1)}$.
**A)** $\frac{16 \times 3^{-k}}{9}$
**B)** $\frac{-16 \times 3^{-k}}{9}$
**C)** $3^{-k}$
**D)** $0$
**E)** $\frac{3^{-k}}{9}$

Present the answer in LaTex format: \boxed{Your answer}
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