Observing the size of a herd of elephants that are all the same species would be an observation at the level.

question 3 options:

community

ecosystem

population

individual

The correct answer is option "population".

Explanation:

In ecology, a population is defined as a group of organisms living in a particular area or region. An observation of a herd of elephants will be a study at the population level, since it is comprised of a limited number of individuals all belonging to the same species. A study of a community would involve observing different species and their interactions, while a study of an ecosystem would involve studying living and non living components over an extensive geographical region.

hello there the answer is d

the answer to your question is tooth decay.