Question

has taxonomy changed in the past 100 years?

yes, because scientists have made changes to the system as we have learned more about the natural world.

yes, because scientists have regularly changed the type of system used to classify living things.

no, because no new organisms have been discovered for a long time.

no, because scientists have agreed about the best ways to classify living things for a long time.

Explanation:

Taxonomy (classification of organisms) evolves as scientific knowledge of the natural world (e.g., new species, evolutionary relationships) grows. Scientists update the taxonomic system to reflect new discoveries/understandings, so it has changed over 100 years. Other options are incorrect: B falsely claims "regularly changed system type" (the basic taxonomic framework is consistent, with updates to details), C is wrong as new organisms are discovered, D is wrong as scientific understanding of classification has evolved.

Answer:

A. Yes, because scientists have made changes to the system as we have learned more about the natural world.