Answer:
a. 200,000 years ago.
Step-by-step explanation:
Scientists believe that Homo neanderthalensis appeared about 200,000 years ago. The name Homo neanderthalensis was given to them because first evidence of their existence was found in Germany near Neander Tal. Their period of existence is part of the Pleistocene period and they are considered as the immediate ancestors of modern humans (Homo Sapiens).