
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
At the start of the school year, 60% of students in Ms. Lee's class stated they preferred "Science" over "Maths", while 40% preferred "Maths." By the end of the year, these preferences shifted to 80% in favor of "Science" and 20% for "Maths." Find the degree of change, denoted as $y\%$, in students' subject preferences. What is the difference between the maximum and minimum possible values of $y\%$?
A) 10%
   B) 15%
   C) 20%
   D) 25%
   E) 30%

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