If Individuals Who Sit in the Back of the Classroom

question 55

Multiple Choice

If individuals who sit in the back of the classroom receive lower grades on average than the rest of the class, does that mean that sitting in the back of a classroom causes one to perform poorly on exams?

• A) Not necessarily. The reoccurrence of a certain relationship between two variables does not necessarily imply causation.
• B) It is not possible for an economist to determine causation between variables.
• C) The reoccurrence of such a relationship is sufficient evidence that sitting in the back of a classroom will lead to lower grades.
• D) The reoccurrence of such a relationship is sufficient evidence that students who receive low grades prefer to keep a low profile and always sit in the back of the classroom.

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Definitions:

Lymphoid Organ

Lymphoid organs, including the lymph nodes, spleen, and thymus, are part of the immune system and play a role in producing, storing, and carrying white blood cells.

Lymphatic Vessel

A network of thin tubes that transport lymph, a fluid containing white blood cells, throughout the body.

Lymph-collecting Vessel

Part of the lymphatic system, these vessels carry lymph, a clear fluid containing white blood cells and waste products, back towards the heart.

Lymph Trunk

Large lymphatic vessels that drain lymph from different parts of the body and empty into the venous system.