Colostrum is yellow coloured, thick and sticky milk. It is the first milk secreted by the mammary gland of females after a few hours of delivery for a few days. It contains more lactalbumin and lactoprotein than milk which is secreted later. It also contains immune cells (lymphocytes) and antibodies like IgA, IgG and IgM that helps in providing immunity to the newborn. So, the correct option is B.