Maize plants are resistant to maize stem borers due to

The correct option is D low nitrogen, high aspartic acid and low sugar content
Agricultural pests are organisms that attack agricultural crops and destroy them, leading to huge crop losses. Some crop plants naturally develop resistance to pests as a result of morphological, physiological or biochemical characteristics in them.

In maize crop certain biochemical characteristics like low nitrogen, low sugar and high aspartic acid content helps resist against maize stem borers (insect larvae which bore into plant stems).