Number of individuals of the species in the area. For example a school of fish requires a large amount of individuals to avoid inbreeding. A species that is very imbred is the Northern Elephant seal, having originated from a few select individuals after being nearly driving to extinction. Although these seals have made a meraculous recovery, they suffer from their inbreeding with damage to their spines and cateracts.
D. seems the most probable since plastic is barely biodegradable.
It is not what you thing it is but the answer is true
The stem has more things to transport that's why it has more vascular bundles. The roots only get water from the ground and moving nutrients from the soil to transfer it to the stem. Having more vascular bundles helps the stems to transfer things to leaves and other parts of the plants.
