Answer:
When two articles provide different kinds of information about the topic.
Step-by-step explanation:
When information is given by two or more different sources, it is difficult to try to integrate the sources together. Moreover, the integration has to be done in such a way that the important details are not left out from any of the sources.
To integrate information from two different sources, we have to look at the kinds of information provided in the sources. And integration can be done if two articles provide or contain information about the same topic. This is when the information from the two different sources must be merged or taken together.
Thus, the correct answer is the second option.