Answer: b
Explanation: because it fits in there
The correct answer is time/chronological order because chronological order is the sequence of events in a story, and if you put them in at the correct time you get an understandable paragraph, story, etc...
To make it to the ocean was their goal
Infectious diseases were common
Fields of wild grass were everywhere
New settlements will be established in the west
I hope that a few of these may help :)