
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
In quadrilateral $ABCD$ with diagonals $AC$ and $BD$, intersecting at $O$, $BO=5$, $OD=7$, $AO=9$, $OC=4$, and $AB=7$. Find the length of $CD$.
A) 9
B) 10
C) 11
D) 7
E) 12

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