<p>A. The normal growth curve by analyzing the absorbance at 600 nm. B. The normal growth curve by counting the CFU. C. The assessment of toxicity of NP-Ag in <i>E</i>. <i>Coli</i>. growth by plotting the curve of absorbance. D. The toxicity of NP-Ag in <i>E</i>. <i>Coli</i>. growth by CFU counting.</p