The most appropriate answer is B !!
Covalent bond is formed by sharing of electrons !!
A. An octopus
An organism is an individual animal, plant, or single-celled life form.
The octopus is the only living thing listed so that is why it is the example of an organism
Gold alloys consist of most commonly Nickel!
Most commonly used in things like jewelry so it doesn't have such a heavy weight.