Final answer:
The princess would send her lover to the tiger as a test of bravery.
Step-by-step explanation:
The reason why the princess would send her lover to the tiger is a) Test of bravery. In the story, the princess had a unique way of determining the guilt or innocence of someone accused of a crime. She would make the accused choose between two doors, one leading to a beautiful lady and the other to a hungry tiger. If the accused chose the door with the beautiful lady, it meant he was innocent. If he chose the door with the tiger, it meant he was guilty of the crime. In this case, the princess may have sent her lover to the tiger to test his bravery and prove his innocence.