Achondroplasia, the most common type of human dwarfism,affects 1 in 15,000 to 1 in 40,000 individuals. Many cases ofachondroplasia are the result of a spontaneous mutation. Afterthe mutation occurs, however, it becomes an autosomaldominant trait.Two individuals with achondroplasia had a son of average heightand two other sons and a daughter with achondroplasia. Whichof the following statements do not explain how the parents canhave a child of äverageḧeight.The äverageḧeight child is homozygous d