Which action is the best example of a direct observation

Since you didn't have any extra information about the question I'll be presenting an example from my own textbooks that I've used.

An example of a direct observation is listening to a cricket chirp at night, and counting the number of chirps per minute.

Direct Observation is where the evaulator watches the subject in their usual habitat without disrupting or altering it.

The answer is D Determining the seal population of an island by counting seals in 10 square meters of the island on e2020

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.