Question

older ocean exploring robots are attached to a ship by a cable
daniela rus, who directs the computer science lab at mit, thinks robots like sofi may offer solutions to these challenges. rus and her team work in a new field called soft robotics. theyre making robots out of soft, elastic materials such as silicone rubber.
with sofi (which is short for \soft robotic fish\), rus and her team wanted to create an undersea explorer that would fit right in with her environment. in other words, they needed sofi to look as fishlike as possible. so they designed her with a sleek, small fish shape. the team also designed sofi to act like a fish. her size, shape, and rubbery surface allow her to swim close to delicate ocean life. her flexible tail swishes smoothly from side to side, like a real fish. it moves her forward and creates no more movement than the tail of any other fish.
what did daniela rus and her team need most from sofi?
they needed sofi to be constructed from soft materials.
they needed sofi to fit in with the underwater environment.
they needed sofi to be named for a \soft robotic fish\

Explanation:

The text mentions that Rus and her team wanted to create an undersea explorer (SoFi) that would fit right in with the underwater environment. They designed SoFi to look and act like a fish (fish - like shape, rubbery surface, flexible tail) so that it could swim close to delicate ocean life. This indicates that fitting in with the underwater environment was a key need.
The first option about being constructed from soft materials is part of the field (soft robotics) but not the main need emphasized in the context of creating SoFi as an undersea explorer. The third option about the name is just a fact about the abbreviation of SoFi and not a need.

Answer:

They needed SoFi to fit in with the underwater environment.