Figure P8 shows a spring-mass system consisting of multiple linear springs arranged in a combination of series and parallel connections. 

The top three springs with stiffness k are connected in parallel to a rigid bar. This bar is then connected to the mass M through three identical springs (each of stiffness 2k) arranged in parallel configuration.

Which of the following correctly represents the

Assume all springs are linear, massless, and deform only in the vertical direction.

Select the correct answer.

Figure P8. Spring and mass system.