A slippery slope argument that Brown considers is that if we allow performance enhancing drugs then ...

A slippery slope argument that Brown considers is that if we allow performance
  enhancing drugs then it is difficult to draw the line at bionic surgical enhancements of the
  body of the athlete. In response, Brown states that
 
  a. such bionic enhancements are the stuff of science fiction, and their development is
  not plausible, so this is not a genuine concern.
  b. it is easy to draw the line: drug enhancements could be allowed while mechanical
  surgical enhancements are prohibited.
  c. this is a large and difficult issue that cannot really be resolved until the technology is
  actually available for examination.
  d. both bionic and drug enhancements of athletic performance are legitimate: the goal is
  improved athletic performance, and the means are irrelevant.
  e. while such bionic surgical athletic enhancements might someday be reality, they
  would be so burdensome and invasive that few athletes would desire them, and peer
  pressure from other athletes would prevent their use.