An observation is received directly or indirectly by

Hearing

Seeing

Tasting/touch

All of the above

D. All of the above.

Explanation:

An observation is received directly or indirectly by all of the above. When observing things, you need to visually be able to see what is being observed, and be able to touch hear and even taste. This ensures that you can get the best out of the observation.

All of the above

Explanation:

because these are all senses of the body and therefore you're receiving signals from all of them all the time