Which of the following describes a function of the endoplasmic reticulum within a cell?

what are the options

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added