Which technique involves reviewing documents to gather necessary information?

The correct answer is the document analysis technique because it specifically focuses on the thorough review of existing documents to extract relevant information that can be used in various business analysis tasks. This technique is valuable for understanding the context, requirements, and system functionalities documented in texts like business plans, project charters, and requirement specifications. By analyzing these documents, a business analyst can identify crucial insights without needing direct interaction with stakeholders, thereby streamlining the information-gathering process.

Other options may relate to gathering information but do not emphasize the action of reviewing documents. For instance, a data gathering technique covers various methods used to collect information, such as interviews and surveys, but does not specifically highlight document reviews. Similarly, stakeholder engagement methods focus on building relationships with those involved in a project rather than solely examining documents. Lastly, the requirements elicitation process generally encompasses a range of activities used to discover and define requirements from various sources, which may include document analysis but is broader in scope. Thus, the document analysis technique stands out as the most accurate choice for the action described in the question.