
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
Consider positive integers $n$, and a function $f(n) = \frac{\sigma(n)}{n}$, where $\sigma(n)$ is the sum of all positive divisors of $n$. Evaluate $f(640) - f(320)$.
A) $\frac{1}{320}$
B) $\frac{2}{320}$
C) $\frac{3}{320}$
D) $\frac{4}{320}$
E) $\frac{5}{320}$

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