How can you distinguish between simple and mixed triacylglycerols?

Simple triacylglycerols are unsaturated, while mixed are saturated.

Simple triacylglycerols have different fatty acid chains, while mixed have identical chains.

Simple triacylglycerols have identical fatty acid chains, while mixed have different chains.

Simple triacylglycerols have no glycerol molecule, while mixed have one.