In the frame shown in the figure (not to scale), all four members $\text{(AB, } \mathrm{BC}, \mathrm{CD}$, and $\mathrm{AD})$ have the same length and same constant flexural rigidity. All the joints $\text{A, B}$, $\mathrm{C}$, and $\mathrm{D}$ are rigid joints. The midpoints of $\mathrm{AB}, \mathrm{BC}, \mathrm{CD}$, and $\mathrm{AD}$, are denoted by $\mathrm{E}, \mathrm{F}, \mathrm{G}$, and $\mathrm{H}$, respectively. The frame is in unstable equilibrium under the shown forces of magnitude $\text{P}$ acting at $\mathrm{E}$ and $\mathrm{G}$. Which of the following statements is/are TRUE?
- Shear forces at $\mathrm{H}$ and $\mathrm{F}$ are zero
- Horizontal displacements at $\mathrm{H}$ and $\mathrm{F}$ are zero
- Vertical displacements at $\mathrm{H}$ and $\mathrm{F}$ are zero
- Slopes at $\mathrm{E}, \mathrm{F}, \mathrm{G}$, and $\mathrm{H}$ are zero