When a white cat has a mother who is homozygous dominant that means her mother is having two same dominant alleles of white color (WW) and as the father is homozygous recessive that means he is having two recessive alleles (ww). So when cross between these two individual will occur than offsprings with heterozygous alleles will be produced which will show the dominant phenotype.
W W
w Ww Ww
w Ww Ww
So all the offsprings will be heterozygous for the trait therefore the correct answer is A.
