28. The writer of this passage would possibly not agree with which of the following？
(A) The long-term effects of additional radiation should be considered before wholepopulations begin space travel.
(B) Mutation rates can be tripled through low levels of radiation in each generation.
(C) Prenatal and postnatal development are affected every little by the physicalenvironment.
(D) There is little danger of genetic mutation from medical treatment which has beenneglected by the general public.