Which of the Following Do the Authors Cite as a Potential

Which of the following do the authors cite as a potential drawback to instituting a general precautionary principle with regard to new technologies?

A) The failure to develop new technologies may create just as much risk as a failure to stop new technologies.
B) Speculative and theoretical threats may divert attention away from real, albeit less dramatic, threats.
C) Such a principle may be too abstract to give practical guidance.
D) All of the above