
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
A research team is monitoring the air quality of cities and divides 24 cities into three groups: Group A, Group B, and Group C, with 4, 12, and 8 cities respectively. If stratified sampling is used to select 6 cities, then the number of cities that should be selected from Group B is.

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