
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
A sequence of squares is constructed using identical square tiles such that the length of each side of a square is one tile more than the side of the previous square. The first square has a side length of one tile. How many more tiles does the tenth square need than the ninth square?
A) 16
B) 18
C) 19
D) 20
E) 21

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