Correct answer is (d) In pineapple, stem is modified into stolon
The best explanation: Runners are modified sub-aerial stem that run along the ground and roots develop at nodes. Suckers arise from the underground part of the stem and these roots are present in Mentha. Stolon arises from the base of the main stem and gives rise to a new plant when meets the soil. In pineapple, stem is modified into suckers.