Which of the following statements about class action lawsuits is false? 

a. Class-action lawsuits encourage multiple lawsuits for the same case. 

b. Class-action lawsuits encourage litigation when no individual plaintiff has a claim large enough to justify the expense of litigation. 

c. Law firms typically work on a contingent-fee basis for class-action lawsuits. 

d. Class-action lawsuits often follow significant declines in the stock price value for a company.