I'm pretty sure the answer would be A. Chromosomes contain one or more genes.
Conifer tree is the tree that the leaf is slender like needle, it is evergreen tree more, material is general softer, some contain colophony , reason calls soft material again, its grows in elevation 100 ~ 1500 meters commonly, have economy and ornamental value.Conifers appeared 280 million years ago before any other trees.Conifers are believed to be the oldest trees on earth。
In primary succession, newly exposed or newly formed rock is colonized by living things for the first time. In secondary succession, an area that was previously occupied by living things is disturbed, then re-colonized following the disturbance.