When there is a smaller difference between high and low tide, it is a neap tide. On which day did the observer experience a neap tide?

Neap tide occurs due to the position of the moon and the sun.

Neap tides occur during the first and third quarter moon. When the moon appears "half full." NOAA's tide and tidal current happens due to the position of the moon and the sun so we can conclude that Neap tide occurs due to the position of the moon and the sun.

Learn more about tide here:

is in the form atp or adenosine triphosphate

the correct answer is:

a population changes in response to a change in the environment.