Hello Gordon,
In general, students will invariably choose the exam with the highest grade. If this applies to your case, you could simply use a grade formula, something like =max([ [examA] ],[ [examB] ]). You will find the correct syntax and more information on how to use grade calculations in MoodleDocs at https://docs.moodle.org/400/en/Grade_calculations
In general, students will invariably choose the exam with the highest grade. If this applies to your case, you could simply use a grade formula, something like =max([ [examA] ],[ [examB] ]). You will find the correct syntax and more information on how to use grade calculations in MoodleDocs at https://docs.moodle.org/400/en/Grade_calculations