Explanation:

- A says to B that he will give a sum of rupees five hundred if B marries his daughter.

- This statement refers to a future event that must occur for the promise to be fulfilled.

- Explanation of Options:

- Vested Right:

- A right that is already secured and doesn't depend on future events.

- Contingent Right:

- A right that depends on a future event that is uncertain.

- The right becomes enforceable only if the condition is fulfilled.

- Correct option: This scenario fits as the payment depends on B marrying A's daughter.

- Primary Right:

- The main right arising from an agreement or obligation itself.

- Secondary Right:

- A right that comes into play to enforce or compensate for a violation of a primary right.

- Answer:

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