In the example given, the frizzle fowl is exhibiting incomplete dominant heterozygous phenotype.
a) This is an example of an incomplete dominant heterozygous phenotype which gives rise to three different offspring.
P A/a (frizzle) X A/a (frizzle)
F1 1A/A (normal): 2 A/a (frizzle): 1 a/a (wooly)
b) For getting mass frizzle pair breeding should happen between a normal (A/A) and a Wooly (a/a), which would produce frizzle birds (A/a).