This single-celled organism moves by a flagellum and has a unique eye spot to detect light A. Euglena
B. Amoeba
Paramecium
D. Volvox

the answer is euglena

euglena have both animal and plant characteristics.

the eyespot indicate that it has an animal characteristics.

And it also have chloroplasts that indicate

has a plant characteristics.

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above