Directions: Fill in the blank with the correct option.

________the rainfall was adequate this year, the mango trees still did not produce a high yield.

The correct answer is 'Although' because it shows contrast between the adequate rainfall (positive condition) and the lack of high yield (negative result). 'Although' introduces a concessive clause. 'Since' and 'Due to' suggest cause and effect, which would mean the trees should have produced well. 'In spite of' needs to be followed by a noun phrase, not a clause.