The correct answer is A. True
Step-by-step explanation
A case book is a source that compiles or includes one or more investigations or law cases, this contains information that serves as evidence to develop investigations or study a case. On the other hand, these pieces of information can be primary or secondary sources as they can include original photos, documents, letters, books, testimonies or laws that are primary sources or secondary sources such as analysis or reports of primary sources. Additionally, these case books are mainly used by investigators or lawyers who use them to group everything related to the cases they are responsible for. So, the correct answer is A. True.