The question asks which of the four options demonstrates the associative property of addition.

The associative property of addition states that the grouping of numbers being added does not affect the sum. In other words, $(a + b) + c = a + (b + c)$.

Let's analyze each option:

1. Option 1: $2 + (3 + 4) = (3 + 4) + 2$
   This changes the order of addition, but it doesn't involve regrouping. It shows commutativity, not associativity.

2. Option 2: $3 + 4 + 2 = 2 + 4 + 3$
   This changes the order of the numbers but does not group them differently, which also shows commutativity.

3. Option 3: $(3 + 4) + 2 = 3 + (4 + 2)$
   This is an example of the associative property because it shows regrouping: $(a + b) + c = a + (b + c)$.

4. Option 4: $(3 + 4) + 2 = 2 + (3 + 4)$
   This changes the order of the numbers, which again demonstrates the commutative property.

Thus, Option 3 is the correct example of the associative property of addition.

Would you like more details or have any questions?

Here are 5 related questions to further explore this topic:

1. What is the difference between the associative and commutative properties?
2. Can the associative property be applied to multiplication as well?
3. How does the distributive property differ from the associative property?
4. Can the associative property be used with subtraction or division?
5. Why is the associative property important in algebra?

Tip: Associative property only involves changing the grouping of numbers, not their order!