Explanation:

- Correct Answer: Colostrum

- Colostrum is a nutrient-rich fluid secreted by mothers after childbirth. It boosts a baby's immune system and helps fight infections.

- Sebum:

- Sebum is an oily substance secreted by the sebaceous glands in the skin. It helps to moisturize and protect the skin, but is unrelated to lactation.

- Synovia:

- Synovial fluid, or synovia, is a viscous fluid found in joints. It reduces friction between joint surfaces, facilitating smooth movement.

- Cerumen:

- Cerumen, or earwax, is secreted in the ear canal. It protects the inner ear from dust and microorganisms but is unrelated to breastfeeding.