Answer:
"People who move to a new city don't always have it easy. They go through much tribulation as they try to set up a new home and make new friends in a place unknown to them."
Step-by-step explanation:
The gap in these lines according to the correct use of part of speech should be cover with a noun, from the given options the only noun that we have is tribulation which fits perfectly in the space not only because of its functions but also because of its meaning conveying the clear message that people have to face some conflicts and difficulties during the process. The other three given options are adjectives that can't be used in that position.