D looks like the oldest one because there is barley anything there. if not then I would do b
1. Naked Seeds, Gymnosperm means 'naked seed' and these were the earliest trees to evolve. They do not produce flowers and have seeds which are directly exposed to the air for wind pollination. Pine cones are one example. For ease you might think of the gymnosperms as conifers, such as yew and Scots pine.
Answer:
Oil is known as Petroleum.