Which magnet is the strongest?

This task is about investigating the strength of magnets.
Your task is to find out which magnet is the strongest, by using the equipment you have been given.
 
a)
Explain to your teacher how you will find this out. Now carry out your plan.
b)
For each magnet draw the magnet's shape and then write down your results in the boxes below.
 
 
Drawing of Magnet
Results
Magnet A
 
 
 
 
 
 
 
Magnet B
 
 
 
 
 
 
 
Magnet C
 
 
 
 
 
 
 
 
c)
 
Which magnet is the strongest?   _______________
Give a reason for your answer.