<span>i would say D because you HAVE to know how to plan because it is research so you have to know how to research so D. hope this helps </span>
It is during the falling action
The relative clause in the given sentences are shown in option (d) or (iv): "that serve the needs of the population"
<h3>What is a relative clause?</h3>
"Who, whom, that, and which" are relative clauses. These can also be referred to as Relative Pronouns, and they are used to provide more information about a place, person, or thing.
Therefore, In this statement, you could alternatively use which instead of that.
Check out the link below to learn more about the relative clause;
brainly.com/question/766213
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Jacket and tie i believe is the answer
correct answer is sybousis