Answer: A.
Since the load is not moving, the system is in equilibrium.
The weight W of the load is downwards.
Consider the rod XZ. There should be a tension along this rod from Z to X for the system to be in equilibrium. [B and C are incorrect]
Now, consider the force in XZ and the weight. The weight acts downwards and the force in XZ has a component vertically down. So, we need a force with having a component vertically up, so that the vertical forces on the system is in equilibrium.
Thus, the force should be from Y and Z. [D is incorrect]
If the forces were as shown in choice B, the rod would bend. The resultant vertically downward force would be greater than the vertically upward force since the magnitudes of W and the force in YZ (represented by their lengths) would be greater.
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