
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
If $\theta$ is an acute angle, $\sin 2\theta = a$, and $\cos 2\theta = b$, calculate the expression $\sin\theta + \cos\theta$.
**A)** $\sqrt{(1+b)/2} + \sqrt{(1-b)/2}$  
**B)** $\sqrt{b+1} + \sqrt{a+b}$  
**C)** $\sqrt{(1+b)/2} - \sqrt{(1-b)/2}$  
**D)** $\sqrt{2a} + b$

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