The alternate idea here, would be that wave 1 was actually an 'a' and wave 2 was actually a 'b', if so this would make wave 3 a 'c'. However, this idea is invalidated as wave 3 has made it based the 100% fib extension level of wave 1.
Only 2% of wave 3's don't make it passed the 100% fib extension level of wave 1, if this occurs, there is a high chance a corrective formation (a,b,c) is evident and not a motive wave formation (1,2,3,4,5).