Which of the Following Is a Specialization Hierarchy Disjoint Constraint

question 18

Multiple Choice

Which of the following is a specialization hierarchy disjoint constraint scenario in case of partial completeness?

• A) Subtype discriminator can be null.
• B) Subtype discriminator cannot be null.
• C) Each supertype occurrence is a member of only one subtype.
• D) Each supertype occurrence is a member of at least one subtype.

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Definitions:

Thermoacidophiles

Microorganisms that thrive in extremely hot and acidic environments, such as hot springs and hydrothermal vents.

Methanogens

Microorganisms that produce methane as a metabolic byproduct in anoxic conditions, often found in wetlands or the guts of animals.

Halophiles

Microorganisms that thrive in high-salt environments, often found in places like salt lakes and the Dead Sea.

Prokaryotes

Unicellular organisms that lack a distinct nucleus and membrane-bound organelles, including bacteria and archaea.