Answer:
Option 4 => only different angles for theta 4, Theta 3 should have the same values in both cases.
Step-by-step explanation:
The vector loop of Section 4.6 that was made as the reference diagram has the vector loop closing itself and the vectors summing around loop zero. Also, it has one DOF mechanism and the vector length is equal to the vector link.
NOTE: Kindly check the attached file or picture for the diagram of Section 4.6 diagram.
We can see from the diagram below that the V3 and V4 can be determined or Calculated with parameters such as theta 2, all links length and length d.
Therefore, the cross and the open configurations of the circuit will produce from the diagram will be " only different angles for theta 4, Theta 3 should have the same values in both cases."( That is option 4)