Prions are killed by:

Ans. is 'd' i.e., Autoclave and NaOHPrions can be destroyed by one of these four options:Option 1. Autoclave at 134degC for 18 minutes in a prevacuum sterilizer.Option 2. Autoclave at 132degC for 1 hour in a gravity displacement sterilizer.Option 3. Immerse in 1NNaOH(1NaOHis a solution of 40gNaOH 1Lwater) for 1 hour; remove and rinse in water, then transfer to an open pan and autoclave (121 degC gravity displacement sterilizer or 134degC porous prevacuum sterilizer) for 1 hour.Option 4. Immerse in 1NNaOHfor 1 hour and heat in a gravity displacement sterilizer at 121degC for 30 minutes, then clean and subject to routine sterilization.