Lena found the greatest common factor (GCF) of 24ab2c3 and 30a2b3c2 to be 6abc2 by using these steps:
Step 1: GCF of 24 and 30 is 6
Step 2: Highest shared power between a and a2 is a
Step 3: Highest shared power between b2 and b3 is b
Step 4: Highest shared power between c3 and c2 is c2
In which step did Lena make a MISTAKE?