
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 phone number of 8 digits, expressed as $d_1d_2d_3d_4d_5d_6d_7d_8$, is deemed structured if the digits form a palindrome, meaning $d_1 d_2 d_3 d_4 = d_8 d_7 d_6 d_5$ in that exact order. Assuming each digit can take on values $0$ through $9$, find how many such structured numbers exist.
A) 9000
B) 9500
C) 9750
D) 10000

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