
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 triangle $DEF$, if the area is $81$ square units and the geometric mean between sides $DE$ and $DF$ is $15$ inches, determine $\sin D$.
**A**. $\dfrac{18}{25}$
**B**. $\frac{3}{5}$
**C**. $\frac{18}{27}$
**D**. $\frac{4}{5}$

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