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, 2k, and 3k are connected in parallel to a rigid bar. This bar is then connected to the mass M through two identical springs (each of stiffness k) arranged in series.

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.