In the following question, out of the four alternatives, select the alternative which will improve the underlined part of the sentence.
The Bishnoi community of Rajasthan and parts of Punjab believe that crop yield increase in fields where the blackbuck had grazed.
1
that crop yield increase in fields where blackbuck were grazing
2
crop yields increases in fields where blackbuck had grazed
3
crops yields decreases in fields where blackbuck was grazing
4
crop yields increase in fields where blackbuck was grazing