B. less likely to be filed by leased employees than by contract employees
C. less likely to be filed by contract employees than by permanent employees
文中leased，contract employee和permanent employee是对应的，b比较错了对象，field这里大概是 引起导致 之类的意思。contract/leased employee 不大会去跟employer闹，这是文中的信息，所以现在在管理者里有转用这类employee的行为。 | 
