Engineered Proteins Can Be Studied in Their Natural Environment in the Cell

Engineered proteins can be studied in their natural environment in the cell. Natural proteins are engineered to contain a tag or a fusion protein in order to ____________.
I. improve protein stability at high temperatures
II. detect the localization of the natural protein in the cell
III. analyze the level of expression in the cell
IV. detect interactions with potential protein ligands in the cell
V. improve stability of the protein in the cell

A) I and II
B) II, III and IV
C) I, III and V
D) II, III and V
E) I and IV