The girl's eyes were deep blue oceans. This is the correct option.
Figurative language is a means writers or speakers use to express emotions, mainly. They do not use language to refer directly to reality but to tell what idea they have of relality. In the example, the writer / speaker compares the girl's eyes to oceans. The girl's eyes must have been blue and this colour must have activated in the speaker / writer 's mind the image of an ocean. Therefore, the writer / speaker sees the eyes like oceans but they are not real oceans. The speaker / writer must have got attracted by the colour of the eyes. Through figurative language, the speaker / writer shows his / her attraction.
These options are not right:
-I am very cold. ( This expresses a real state. )
-The melting snow froze on the sidewalk.( This refers to reality. It can be seen .There is real evidence).
-The boy jumped into the air. ( We could have seen the boy doing so).