
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
Consider the sequence 
$1,-2,3,-4,5,-6,\ldots,$
whose $n$th term is defined by $(-1)^{n+1}\cdot n$. Determine the average of the first $150$ terms of the sequence.
A) -1  
B) -0.75  
C) -0.5  
D) 0  
E) 0.5

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