Secondary data collection refers to the process of gathering information that has already been collected by someone else for a different purpose. It involves using existing data sources such as books, articles, reports, and databases to extract relevant information. The options provided in the question are different methods of primary data collection rather than secondary data collection.

Primary data collection methods involve directly gathering information from individuals or sources specifically for the purpose of the current research. On the other hand, secondary data collection involves utilizing existing data sources that were collected for a different purpose. This data can be obtained from various sources such as government publications, research papers, company reports, and online databases.

There are several methods of secondary data collection, which are as follows:

1. Published Sources: This refers to obtaining information from books, magazines, journals, and other published materials. These sources can provide valuable data on a wide range of topics, and they are often reliable and well-researched.

2. Government Sources: Governments collect and publish a vast amount of data on various topics such as demographics, economics, health, education, and more. This data can be accessed through government websites, statistical agencies, and other official sources.

3. Research Reports: Many research studies and reports are conducted by organizations, research institutions, and think tanks. These reports often contain valuable data and insights related to specific industries, markets, or social issues.

4. Online Databases: There are numerous online databases that provide access to a wide range of secondary data sources. These databases may include academic journals, market research reports, industry profiles, and more. Examples of such databases include JSTOR, ProQuest, and EBSCOhost.

5. Previous Research Studies: Existing research studies can serve as a valuable source of secondary data. Reviewing previous studies in the same field can provide insights, data, and references for the current research.

6. Company Reports: Many companies publish annual reports, financial statements, and other documents that contain valuable information about their operations, performance, and industry trends. These reports can be a valuable source of secondary data for market research and analysis.

In conclusion, the correct answer to the question is option 'D' - None of these. The options provided in the question are methods of primary data collection, whereas secondary data collection involves gathering information from existing sources such as published materials, government sources, research reports, online databases, previous research studies, and company reports.