What is the correct definition of the problem/solution text structure?

1. Looks at the cause and effect relationship of a topic

2. Looks at the similarities and differences between two topics

3. Looks at the description of a topic

4. Looks at the problem and solution relationship of a topic

5. Looks at the sequence of events related to a topic

Which of the following is an example of a Key or Signal word for problem/solution text structure?

1. For example

2. Solution

3. After