Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to raise a smart baby [title] Bond with your baby. [step] Experts note that, upon birth, a baby's brain is concerned with safety. Without a feeling of safety, your baby will be unable to learn as well as they could.

Ending1: Developing feelings of coolness will signal to your baby that you are confident about handling baby products. [substeps] Place your baby's carebook in the appropriate place and read every day about your baby's developmental development. Ending2: For the first few years of life, your baby will be solely dependent on humans. However, they can grow out of the process if they don't learn to differentiate between their new environment and humans' homes. Ending3: Avoid letting your baby have contact with both adults and their children. Sexual activity should never be encouraged, especially during the first six months of your baby's life. Ending4: Immediately after birth there are a number of steps you can take to make your baby feel secure, all of which are related to bonding with your child. [substeps] Skin-to-skin contact helps bonding and brings a feeling of safety.

Answer format: ending1/ending2/ending3/ending4