Literature review provides:

The correct option is Discussion of works already researched in a relevant subject area.

Step-by-Step Explanation:

1. Definition of a Literature Review: A literature review is a comprehensive survey and critical evaluation of existing scholarly sources (such as books, journal articles, and theses) relevant to a specific research topic or question.
2. Understanding the Purpose: The primary goal of a literature review is to demonstrate to readers that the researcher has a thorough understanding of the existing body of knowledge, including major theories, methodologies, debates, and gaps in the current research. It is essentially a synthesized discussion of what has already been studied and written about the subject area.
3. Analyzing the Options:
• Citation details: While citations are included in a literature review, the review itself is not merely a list of citations; it is a structured narrative and critical discussion.
• Discussion of works already researched in a relevant subject area: This perfectly matches the core definition and objective of a literature review, as it involves synthesizing and discussing past research.
• A list of primary sources: A literature review evaluates both primary and secondary sources and integrates them into a discussion rather than just listing them (which is more akin to a bibliography).
• Provides hypothesis of the research undertaken: The hypothesis is a specific prediction formulated by the researcher for their own study and is typically presented in the introduction or methodology, not as the definition of what a literature review provides.