The correct answer is option C, that is, the presence of the nuclear membrane.
Cyanobacteria is a phylum of bacteria that attain their energy via the process of photosynthesis, and are the only photosynthetic prokaryotes possessing the tendency to generate oxygen. As a prokaryote, they are devoid of the nuclear membrane.
Euglena refers to a single cell flagellate eukaryote. It comes under the class Euglenoidea. The species of Euglena are witnessed in salt water and in freshwater. Being a eukaryote, they possess nuclear membrane.
Coevolution happens when the genetic development between two or more species affects the evolution of each other. An example would be hummingbirds and bird-pollinated (ornithophilous) flowers. The ornithophilous flowers give nourishment to the birds with their nectar that has high sugar content. The birds in return aids in the pollination of these flowers.
The correct answer is From east to west
Scientists are still doing research and we just need to be patient. :) :)
