Which of the following statements best describes early labor unionism in California?

Which of the following statements best describes early labor unionism in California?
 
  a. The union movement in California was strong from the very beginning because of the liberal nature of the state.
  b. The most enduring union of this era was the American Federation of Labor because it organized both skilled and unskilled workers along industrial lines.
  c. Opposition to Chinese labor proved a useful strategy in organizing white workers in the state.
  d. All of the above are accurate descriptions of labor organizing in Gilded Age California.