
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
Each row and each column in a $4 \times 4$ grid forms an arithmetic sequence with four terms. You need to determine the value of $Y$, which is located at the second row and third column of the grid. Given the first term of the first row is $3$ and the last term is $18$, and the first term of the last row is $11$ and the last term is $50$.
A) 18  
B) 21  
C) 24  
D) 29

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