
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
Simplify the fifth term in the expansion of \((\frac{a}{x^2} - \frac{x}{a^3})^7\).
**A)** \(\frac{35}{x^2 a^9}\)  
**B)** \(-\frac{35}{x^2 a^9}\)  
**C)** \(\frac{21}{x a^6}\)  
**D)** \(-\frac{21}{x a^6}\)  
**E)** \(\frac{7}{x^3 a^{10}}\)

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