
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 the New Year's Day celebration, a variety show is composed of 6 acts, with the following requirements for the order of performance:  
- Act A must be arranged in one of the first two positions,  
- Act B cannot be arranged in the first position,  
- Act C must be arranged in the last position.  

How many different arrangements of the show's performance order are there?  
    A．36;           B．42;            
    C．48;           D．54

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