Steam explosion pretreatment technique was applied to produce fuel pellets in an experiment that involves four experimental conditions: Results in terms of the fuel properties " C/H ratio" and "lignin content" are shown in the table below: a) What is the main reason for the increase in lignin content due to steam explosion? b) Calculate the "Severity Index, R" for each experimental condition. Determine the percent changes in C/H ratio and lignin content relative to the control, and how these changes vary with R. c) Based on the percent changes in the fuel properties vs. the percent change in the severity index, comment on whether temperature or time appears to have a greater impact on the fuel properties