The correct option is
C There
The correct answer is Option A.
THERE is used to refer to a situation. In the given sentence the reference is to thesituation of a drought before the rain finally came.
Thus in the given sentence, THERE will be the correct and appropriate word that will be used.
THEIR is incorrect because it is used to show belonging to a number of persons previously mentioned.
The remaining options are incorrect because:
Option B- THEY'RE is the contraction of THEY ARE.
Option C- THEIRS is also used to show belonging or association but is used as an object of a verb.
Option D- NO CHANGE is incorrect because Option A is the correct answer.
Thus Option A is the correct answer.