Which of the Following Relational Algebra Commands or Combination of Commands

question 55

Multiple Choice

Which of the following relational algebra commands or combination of commands is capable of retrieving one or more rows of a relation?

• A) Select.
• B) Project.
• C) Join.
• D) Select and Project.
• E) Select, Project, and Join.

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Definitions:

Neuroglial Cells

Supportive cells in the nervous system that provide insulation, nutrients, and structural support for neurons, and participate in signal transmission.

Myelin

A fatty covering that insulates nerve fibers in the brain, spinal cord, and peripheral nerves, speeding the transmission of nerve impulses.

Action Potential

A rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane, a process allowing neurons to transmit signals.

Membrane Potential

Voltage difference across a cell membrane.