Possible Clues:

• Exam for H.S. students
• Its highest score is 5, in brief
• Source of springtime stress for a H.S. student
• A phosphorus match is most convenient
• A nuisance, accepting time needed to get very fit
• Slowest set pace holding up most fit
• Most fit old man's upset before examination
• Exam scored on a scale of 1 to 5, informally
• Foremost of pupils in an exam must be this?
• HS exam scored from 1 to 5