*$_Cast iron vessels are not suitable for the storage of?

• A. Freon
• B. H‚Äö√á√áSO‚Äö√á√ë (95%) at room temperature
• C. H‚Äö√á√áSO‚Äö√á√ë (fuming)
• D. Wet SO‚Äö√á√á