Explain how scientists got the space station up in space. What problem did they
encounter and how was it solved?

scientists got the space station up in space in to small pieces.

Explanation:

The main problem which was faced by the scientist was that there was no powerful rocket which has the ability to lift the whole space station due to its more weight and carry it to the space against the powerful force of gravity. So for solving this problem, space station is taken into pieces into the space and then these pieces should be join to build the space station.

the correct option is option d