ANSWER
[tex]s=\frac{4}{l}[/tex]EXPLANATION
We want to find the equation that models the relationship.
An inverse proportional relationship is generally given as:
[tex]y=\frac{k}{x}[/tex]where k = constant of proportionality
x and y = variables that are related
Therefore, given that the number of possible string sections, s, varies inversely with the length, l, the only option that is in this form is:
[tex]s=\frac{4}{l}[/tex]That is the correct answer.