Select the most appropriate option to fill in the blank.

In Egypt, the sun is warm on the green palm-trees, and the crocodiles lie in the mud and look lazily about them. My companions are building a nest in the Temple of Baalbec, and the pink and white doves are watching them, and cooing to each other. Dear Prince, I must leave you, but I will never forget you, and next spring I will bring you back two beautiful jewels in place of those you have given away. The ruby shall be redder than a red rose, and the sapphire shall be _________ the great sea