Minimum speed to avoid being heat treated

Heat treating is a group of industrial and metalworking processes used to alter the physical,The trapped atoms prevent the crystal matrix from completely changing into its low temperature. Total case depth, min. Salt baths utilize a variety of salts for heat treatment, with cyanide salts being the most extensively used

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.