The correct answer is B. Secondary
Step-by-step explanation:
The word source refers to text, photograph, record or any other material that provides information about some event; additionally, sources can be classified as primary, secondary or tertiary sources. A source is considered as primary if it e is created during or shortly after the event it describes and works as a first-hand account of events. On the other hand, a source is secondary when it summarizes, describes, analyzes, criticizes, etc. a primary source and therefore are not first-hand accounts. Finally, a tertiary source refers to a source that analyzes, summarizes, etc. a secondary source, which makes this type of sources the type of source that is further from the event described.
Considering this, a critical study of a poem by Robert Louis Stevenson is a secondary source because the poem by Robert Louis Stevenson is a primary source considering this describes events that occurred while Stevenson was alive and work as a first-hand account and the critical study analyzes, summarizes and evaluates the poem, which means this document creates a new document based on a primary source, which is exactly the purpose of a secondary source.