Which statement describes the proper use of an anti-static wrist strap?

Which statement describes the proper use of an anti-static wrist strap?

• An anti-static wrist strap should not be used in conjunction with an antistatic mat.
• For optimum grounding, the clip should be attached to a painted section of the computer case.
• An anti-static wrist strap should make contact with the skin.
• The anti-static wrist strip should not be attached to any grounded object.
  

  Explanation: ESD can cause permanent damage to electrical components. An anti-static wrist strap must be worn and grounded when working on a PC. Computer case paints may not be conductive and thus it is better to ground the bare section of a computer case.