Geobacillus stearothermophilus and Bacillus atrophaeus are microbial spore populations used for which type of sterilization process monitoring?​ Geobacillus stearothermophilus and Bacillus atrophaeus are microbial spore populations used for which type of sterilization process monitoring?​ ​

a. Biological
b. ​Mechanical
c. ​Chemical
d. ​Administrative