Which of the Following Is TRUE of Social Smiling

question 130

Multiple Choice

Which of the following is TRUE of social smiling?

• A)It does not occur in response to external stimuli.
• B)It appears during the first month after birth.
• C)It usually appears during sleep.
• D)The external stimulus is typically a face,in the case of young infants.

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Definitions:

IgA

Immunoglobulin A, a type of antibody that plays a crucial role in the immune function of mucous membranes.

IgD

A class of immunoglobulins involved in the immune response, found in small amounts in the body's fluids and tissues.

IgM

Immunoglobulin M, a type of antibody that is produced by the body's immune system as a first response to a new infection.

Lymphokines

Substances secreted by certain cells of the immune system that carry signals locally between cells, and thus have an effect on other cells or the immune response.