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.

Explanation:

The text mentions that Rus and her team wanted to create an undersea explorer that would fit right in with the underwater environment. This means they needed SoFi to look and act like a fish, which is about fitting in with the underwater environment. The other options are either less relevant (being named for a "soft robotic fish" is just a name - related thing and not the main need) or not the most comprehensive (constructed from soft materials is part of it but the overall goal is fitting in with the environment).

Answer:

They needed SoFi to fit in with the underwater environment.