A specimen has a reduced total hemolytic complement as measured by CH50. When individual components ...

A specimen has a reduced total hemolytic complement as measured by CH50. When individual
  components were measured, total C3 was very reduced, but total C4 was within normal limits.
  How can these results be best explained?
 
  A) There has been a recent significant activation of the alternate complement path.
  B) The subject has severe liver disease.
  C) There has been a recent significant activation of the classic complement path.
  D) There has been a recent significant activation of the mannose binding lectin complement
  path.