You are answering a USMLE-style medical question. Question: Three patients present to the pediatrician for routine well-child visits. The first child’s mother reports that he seems to be breastfeeding well and voids at least eight times per day. His stools are a yellow color, and he does not seem to be straining. In the office, he can lift his head and chest when in the prone position, and he can track an object with his eyes to the midline. His hands remain fisted 50% of the time. The second child’s parents report that she is doing well at home and seems to enjoy playing with her older brother. In the office, she can roll from supine to prone and can transfer her rattle from hand to hand. She cannot yet say any words. The third child’s father reports that he is starting to explore the world around him. He has begun taking independent steps at home. In the office, he seems to recognize the name of several objects, but he cannot follow the direction to “grab the ball.” All three children are assessed as developmentally normal. Which of the following represents these patient's respective ages? Options: A) Ages 1 month, 4 months, and 9 months B) Ages 2 months, 4 months, and 12 months C) Ages 2 months, 6 months, and 9 months D) Ages 2 months, 6 months, and 12 months Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.