Which of the following factors lead to resistance to maize stem borers?
i) High aspartic acid content
ii) High nitrogen content
iii) Low sugar content

i and iii

Maize stem borer is the most notorious pest of maize crop which damages the crop considerably and reduces the yield by 10-20% but sometimes the losses may be up to 80%. High aspartic acid, low nitrogen content and low sugar content are some factors which are responsible for resistance to maize stem borer.