Step 1: Understanding the Concept
Colostrum is the yellowish milk produced during the first few days after childbirth.
Step 2: Contents
It is rich in proteins and lactose, low in fat, and carries large amounts of IgA antibodies.
Step 3: Importance
These antibodies give the newborn passive immunity against infections.
Step 4: Conclusion
Colostrum contains proteins, lactose and IgA.
Final Answer:
Colostrum contains proteins, lactose and IgA.
\[ \boxed{\text{(D) }\text{Proteins, Lactose, IgA}} \]