A full term baby,exclusively breast feed,at the end of 1 week was passing golden yellow stools and was found to have adequate hydration with normal systemic examination.The weight of the baby was just same as it was at birth.The pediatrician should now advise:

• A. Give oral solution with breast feeding
• B. Start tap feeding
• C. Investigate for lactic acidosis
• D. Reassure the mother than nothing is abnormal