To choose the peanut butter we can calculate the ratio price to weight for each one:
[tex]\begin{gathered} \text{option 1:} \\ \frac{3.20}{40}=0.08 \\ \text{option 2:} \\ \frac{1.92}{16}=0.12 \end{gathered}[/tex]We can see that for option 1 see we pay 0.08$/oz and for option 2 0.12$/oz, so the better choice is option 1.