Which fixative contains picric acid but not acetic acid?

• A. Zamboni
• B. Zenker
• C. Orth
• D. B-5

Answer: (A)

The key idea is to distinguish fixatives by their chemical ingredients, specifically whether picric acid is used and whether acetic acid is present. Zamboni fixative uses picric acid as the active fixing component without including acetic acid in its formulation, so it fits the description of containing picric acid but not acetic acid. The other options are known to include acetic acid in their recipes, which disqualifies them for this specific criterion. So, Zamboni is the fixative that contains picric acid but not acetic acid.