
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
Set $A$ has $30$ elements, and set $B$ has $20$ elements. It is known that at least $10$ elements are common to both sets. What is the smallest possible number of elements in $A \cup B$?
**A)** 35\
**B)** 40\
**C)** 45\
**D)** 50\
**E)** 55

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