Read the following scenario. Then answer the question based on this scenario. Harper is a two-year-old girl in an Early Head Start classroom. She was born six weeks premature, and both she and her mother tested positive for cocaine at birth. Harper was diagnosed with developmental delay and was placed in a foster home during the period in which the mother successfully completed a drug treatment program. Harper thrived in her responsive and caring foster care home, where she had nurturing care with many opportunities for sensory experiences. She also received developmental therapy services through the state early intervention program. At 18 months, Harper was reunited with her mother and has attended Early Head Start for six months. Assessment at the Early Head Start indicates that Harper is meeting all of her developmental milestones. Harper can run and jump, has a vocabulary of 100 or more words, can help pull up her diaper, and is beginning toilet training. Developmental milestones Harper met are A. running and jumping. B. fetal growth. C. overcoming addiction to an illegal substance. D. growth of the spinal cord.