The correct option is
C Color
Detailed step-by-step solution:
As per Option A, the helicopter toys are sorted according to their colors.
According to the table, there are 4 yellow helicopters, 4 blue helicopters, and 4 red helicopters. Therefore, this option is correct.
As per Option B, the helicopter toys are sorted according to their size.
According to the table, there are 4 big, 5 medium, and 3 small helicopter toys. But there are 4 medium and 4 small helicopter toys, therefore, this option is incorrect.
As per Option C, the helicopter toys are sorted based on their shape. But the shape of all the helicopter toys is the same, therefore, this option is also incorrect.
As per Option D, the helicopter toys are sorted based on their size.
According to the table, there are 4 big, 4 medium, and 3 small helicopter toys. But there are 4 small helicopter toys, therefore, this option is also incorrect.
Hence, Option A is correct.