The answer is a C. The offsprings from this generation are from a cross between parents who are heterozygous (one parent) and homozygous recessive. This means that all the offsprings of the filial 1 (one) generation will carry a recessive allele. However, those with an equivalent dominant allele will not exhibit the attached earlobe trait. This is shown by the Punnet square below;
Traits favorable for survival
The population of blue crabs will be difficult for the scientists to count because of unreliable ways and natural phenomenon or occurrence that causes the water's temperature to rise. According to climate reports, year 1999 have warmer temperature and this probably caused the blue crabs to be active, but on year 1990 female blue crabs sustained a normal quantity of production of their species. Thus, the estimated count of population of blue crabs is probably more accurate in year 1990 than year 1999 because of the stable production of the female crabs.
