To Create a Condition That Is True If One or More

question 3

Multiple Choice

To create a condition that is true if one or more rows are obtained when the subquery is executed, you can precede that subquery with which operator?

• A) IS NULL
• B) IS TRUE
• C) IS EXIST
• D) EXISTS

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Definitions:

Antigens

Antigens are substances, often on the surface of pathogens, that are recognized by the immune system, triggering an immune response.

Antibodies

Protein molecules produced by the immune system in response to antigens, which they specifically bind to neutralize or destroy.

Erythrocytes

Red blood cells, which carry oxygen from the lungs to the rest of the body and return carbon dioxide for exhalation.

Leukocytes

White blood cells that are part of the body's immune system, helping to fight infection and other diseases.