Which of the following is a criterion for determining whether an operating segment is separately reportable?

  a. Segment liabilities are 10 percent or more of consolidated liabilities.
  b. Segment profit or loss is 10 percent or more of consolidated net income.
  c. Segment assets are 10 percent or more of combined segment assets.
  d. Segment revenues from external sales are 5 percent or more of combined segment revenues from external sales.