
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
For every $n$, the sum of the first $n$ terms of a sequence is given by $S_n = 3n + 4n^2$. Determine the expression for the $r$-th term of this sequence.
A) $8r + 1$
B) $8r$
C) $7r - 1$
D) $8r - 1$
E) $9r - 1$

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