Read the fragment: “Research focused on second language acquisition (SLA) is no longer directly focused on language teaching as it was in the early stages of the development of this academic area. As such, some questions that guide SLA research include how languages in general are learned and the relation with first language acquisition. The answers to these questions give us a deeper understanding of the nature of language and its complexities, which, in turn, may further aid in language teaching methodologies. Some milestones in the course of SLA research include: contrastive analysis, language transfer, error analysis, and universal grammar." About the contrastive analysis, it is correct the option: