Answer:
As per given Information
we have to find the extension when loaded with given magnitude of force.
Using Formulae
[tex] \bf \: F = Kx \: [/tex]
where, x is extension
Putting the value we get
[tex] \sf \twoheadrightarrow \: 15 \: = 5 \times x \\ \\ \sf \twoheadrightarrow \: \frac{15}{5} = x \\ \\ \sf \twoheadrightarrow \cancel \frac{15}{5} = x \\ \\ \sf \twoheadrightarrow \: 3cm \: = x[/tex]
So, required option is (d) 3 cm