According to John Porter, which term best describes ethnic stratification in Canada?

According to John Porter, which term best describes ethnic stratification in Canada?
 
  a. Vertical mosaic
  b. Sovereign-assimilation
  c. Melting pot
  d. Horizontal integration

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A 1969 study by the Royal Commission on Bilingualism and Biculturalism revealed several demographics on race. For example, British, Jewish, and Asian groups were overrepresented in the managerial, professional, and technical occupations. This concentration of particular ethnic groups in certain occupational areas illustrates how:
 
  a. studies on ethnicity can be unreliable.
  b. genetic factors influence career outcomes.
  c. diversity can negatively impact a society.
  d. ethnicity intersects with social class.