Correct Answer - Option 2 : Magnus effect
When the flow is into air, the atmospheric pressure is equal on all sides around the flow. But when we put something such as a surface on one side of the flow, we are blocking the atmosphere from interacting with the flow from that side, which results in a pressure imbalance between the side that is open to the atmosphere, called Coanda effect.
When a body is submerged (partially or fully) in fluid, it experiences a upward force called buoyancy forces and effect is called buoyancy effect.
If a cylinder is rotated in a uniform stream, there will be an automatic generation of lift force. This effect first observed by Magnus, so called
Magnus effect.