Which of the following is most resistant to antiseptics?: (A) Spore, (B) Prion, (C) Cyst, (D) Fungus
Answer is B. Resistance of organism to antiseptics in decreasing order is as follows:

Prions
Coccidia
Spores
Mycobacteria
Cysts
Small non-enveloped virus
Trophozoites
Gram-negative bacteria (non-sporulating)
Fungi
Large non-enveloped virus
Gram-positive bacteria
Lipid enveloped / medium sized virus (HIV, HBV)