In the lines, the speaker talks about how they grateful that they still had their lives, but they were grief-stricken that their friends' lives had been lost. Before setting sail, they recognize the dead by raising a cry, three times. The best theme choice is that one must mourn before moving on. The ships do not leave port until they have mourned and saluted the lives of their friends who were lost. The other options aren't correct. There is no indicated that sadness destroyed anyone. Even though the speaker talks about the lives lost, he does not speak of them as being lost too soon. The last option is also not correct as there is no mention of lost souls.
