Primary data a. come from firsthand experience and observation. b. are the only type of factual information that should be included in informal reports. c. include printed materials found in libraries or through electronic resources. d. result from reading what others have experienced or observed and recorded.

Option A

Explanation:

From the classification of data, primary data is also known as the root of information, they are data's gotten from the horses mouth, if we are to classify how authentic they are. They are data's that explains true explanation that can't be neglected. It is from primary data that other information's and added on are gotten to become secondary data.

From the option above, option A is what explains what primary data is which is the right and best choice to the question.