Assertion: Transfer of electrons from the split water molecule to P${680}^{+}$ is easy.
Reason: P${680}^{+}$ is the strongest biological oxidizing agent known.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.