
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
The ratio of $a$ to $b$ is $5:4$, the ratio of $c$ to $d$ is $2:1$, and the ratio of $d$ to $b$ is $1:8$. What is the ratio of $a$ to $c$?
A) 10:1
B) 5
C) 4:1
D) 16:3
E) 20:3

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