
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 a $3 \times 3$ block where the elements sequentially increase from left to right, top to bottom starting from 1. First, swap the elements in the first and the last rows, then, sum the numbers on each diagonal. Calculate the positive difference between the two diagonal sums after the row swap.
A) 0  
B) 10  
C) 12  
D) 14

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