Describe the genotypes and phenotypes of the offspring expected from the following parents. ( $\mathrm{H}^{\top}$ represents the normal gene for hemoglobin production, and $H^2$ represents the incompletely dominant allele that causes the formation of abnormal hemoglobin.)
a. $H^2 H^{\prime}$ and $H^2 H^2$
b. $H^{\top} H^{\prime}$ and $H^{+} H^2$
c. $H^{\top} H^2$ and $H^{\top} H^2$