
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 trying to completely cover different checkerboards below by non-overlapping dominoes. Which of these checkerboards CANNOT be covered completely?
- 4x4 board
- 5x5 board
- 5x7 board
- 6x6 board
- 7x3 board
A) 4x4
B) 5x5
C) 5x7
D) 6x6
E) 7x3

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