Answer:
100% of the progeny will be speckled
Explanation:
Available data:
Cross: dark brown crab with a light brown crab
Parentals) BB x bb
Gametes) B B b b
Punnett square)
B B
b Bb Bb
b Bb Bb
F1) Genotype:
4/4 = 100% of the progeny will be heterozygous for the trait, Bb
Phenotype:
4/4 = 100% of the progeny will be speckled