An independent variable is a variable which change is not affected by that of another variable. By process of elimination you can take out B and C. An independent variable can also change so that takes out A. That leaves D.
Sexual means something physical and sexual reproduction is the creation of an offspring.
The answer to this question would be: <span>C) cell type, prokaryotic versus eukaryotic. </span>
In six-kingdom classification, the cell type would be same for each kingdom. A kingdom should only have either prokaryotic or eukaryotic
A different method of reproduction needs an advanced organ and not all kingdom have it. Consumer/producer or unicellular/multicellular classification cant differentiate between the kingdom since one kingdom can have a member with those traits.
To see if the original results are reproducible