The answer is the first one “Testificariamos”
Casandra nesesita una blusa
Cortan because ellos means they and they is plural. Corta would be for ella/el/usted
First Poem:
I don't know what he gave you.
I don't know what I gave you, for a look a world,
for a smile the sky,
For a kiss, I don't know what I gave you for a kiss.