
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 those functions \( f \) that satisfy \( f(x+3) + f(x-3) = f(x) \) for all real \( x \). Find the least common positive period \( p \) for all such functions.
- **A)** \(6\)
- **B)** \(9\)
- **C)** \(12\)
- **D)** \(15\)
- **E)** \(18\)

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