What Is the Meaning of a "Closed" Universe

question 59

Multiple Choice

What is the meaning of a "closed" universe?

• A)The universe is already collapsing back into another cycle.
• B)The universe will someday stop expanding and begin collapsing inward.
• C)The universe will slow down and stop expanding in an infinite amount of time.
• D)The universe is in a steady state, with constant replacement of matter and energy.
• E)The universe will expand forever.

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Definitions:

Melatonin

A hormone produced by the pineal gland that regulates sleep-wake cycles.

Cortisol

A steroid hormone released by the adrenal glands in response to stress or low blood-glucose concentration; plays a significant role in the body's response to stress.

Erythropoietin

A hormone produced by the kidneys that stimulates the production of red blood cells in the bone marrow.

Kidney

A pair of organs located in the abdominal cavity responsible for filtering waste products from the blood and excreting them as urine.