What are plastids known for containing?

Plastids are a group of organelles found in the cells of plants and algae, and they are known for their ability to store various substances necessary for the cell's functions. The correct response highlights that plastids can contain pigments, starch, oil, or protein, reflecting the diverse roles they play in plant biology.

Specifically, chloroplasts—which are a type of plastid—contain chlorophyll, enabling photosynthesis by capturing light energy. Other types of plastids include chromoplasts, which contain pigments that give fruits and flowers their color, and amyloplasts, which store starch. Additionally, some plastids can store oils or proteins, demonstrating their versatility in cellular functions and energy storage.

This comprehensive functionality underscores why the correct option includes a variety of substances, revealing the importance of plastids in both energy production and storage within plant cells.