Which of the following is used as an indicator for plasma sterilization?

For determining the efficacy of moist heat sterilization, spores of Bacillus stearothermophilus are used as the test organism. This is a thermophilic organism with an optimum growth temperature of 55-60oC and its spores require an exposure of 12 minutes at 121oC to be killed. Ref: Textbook of Microbiology by Ananthanarayan, 8th edition, Page 32; 6th edition, Page 27.