
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 sum of the first $n$ terms of an arithmetic progression is given by the formula $3n + 4n^2$. What is the $r$th term of this progression?
**A)** $7r + 1$  
**B)** $8r + 1$  
**C)** $8r - 1$  
**D)** $7r - 1$  
**E)** $9r - 1$

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