David smith and thomas scott (2003) argue for coding based on the finding that at more central locations in the taste system, neurons are tuned broadly, with many neurons responding to more than one taste quality.

Population.

Explanation:

Population coding may be defined as the relationship between the stimulus, individual response and neurons electrical activity. This coding focus that neurons can encode analog and digital information.

The scientists, David smith and Thomas Scott argued for the population coding based on the findings that neurons can tuned broadly at central locations of the taste system. Many neurons are involved in responding to the more than one taste quality.

Thus, the answer is population.

most community's take hundreds of years to become stable

"d.) carbon dioxide and hydrogen sulfide"