The correct answer is option 'D': remarkable increase in brain size. The evolutionary history of Homo sapiens is characterized by a notable increase in brain size. This change is considered to be one of the most apparent and defining features of our species. Let's explore this answer in detail.

Evolutionary History of Homo sapiens:

- Homo sapiens, or modern humans, belong to the genus Homo, which includes other extinct human species such as Homo neanderthalensis and Homo erectus.
- The evolutionary history of Homo sapiens can be traced back to our early ancestors who lived in Africa over 200,000 years ago.
- Over time, several significant changes occurred in the Homo sapiens lineage, leading to the emergence of anatomically modern humans.

Remarkable Increase in Brain Size:

- One of the most significant changes during the evolutionary history of Homo sapiens is the remarkable increase in brain size.
- Fossil evidence shows that our early ancestors had smaller brains compared to modern humans.
- The brain size of Homo sapiens gradually increased over time, particularly in the region known as the cerebral cortex, which is responsible for higher cognitive functions.
- This increase in brain size is believed to be a result of natural selection and evolutionary pressures that favored individuals with larger brains, as it provided them with a competitive advantage in terms of problem-solving, social interaction, and adaptation to changing environments.

Advantages of Increased Brain Size:

- The increase in brain size conferred several advantages to Homo sapiens, including enhanced cognitive abilities, language development, and innovative thinking.
- A larger brain allowed our ancestors to develop more complex social structures, communicate effectively, and create sophisticated tools and technologies.
- The remarkable increase in brain size also facilitated the development of culture and the transmission of knowledge from one generation to the next.
- This cognitive capacity enabled Homo sapiens to adapt to various environments, colonize new territories, and thrive as a species.

Other Changes:

While options a) loss of body hair, b) walking upright, and c) shortening of the jaws are also significant changes during the evolutionary history of Homo sapiens, they are not as defining or apparent as the remarkable increase in brain size. These changes occurred in various stages throughout human evolution and contributed to our species' unique characteristics and abilities. However, the increase in brain size is particularly notable as it distinguishes Homo sapiens from other species and played a crucial role in our species' success and dominance.