The correct answer is C. All of these
Explanation:
A study routine refers to a plan to study everyday or very usual, this routines or plans include include goals of the routine; content that will be study, time it will take, place or zone and materials or elements required for studying, in this way the goals of learning are achieved in an organized way and through consistent study sessions. Considering this, the correct answer is C. All of these, as it necessary to consider the time to study (option A), but also where this will take place (option B).
