Which of These Experiments Would NOT Be a Reason to Fractionate

Multiple Choice

Which of these experiments would NOT be a reason to fractionate bacterial cells?

A) to obtain membrane fractions to study transport proteins
B) to purify ribosome subunits to study translation
C) to obtain periplasmic proteins to study chaperons from that space
D) to obtain cytoplasmic proteins such as FtsZ
E) to study the growth rate of E. coli in the presence of lactose