Final answer:
The Mesopotamians are credited with developing the earliest system of writing, cuneiform, around 3000 BCE. In the Western Hemisphere, the Olmecs arguably developed the first writing system, but it is the Mayan civilization, known for its elaborate hieroglyphs on walls, which stands out among the cultures mentioned.
Step-by-step explanation:
The earliest known forms of writing were developed by the Mesopotamians around 3000 BCE, with their system called cuneiform. This gradually evolved from pictographs to syllabic symbols. On the other hand, wall writings have been associated with various ancient civilizations, including the Mayans, who had a complex written language depicted on buildings and stelae. The Damaidi petroglyphs in China, although not conventional writing, demonstrate the precursor to Chinese characters.
When it comes to the Western Hemisphere, it was the Olmecs who are believed to have developed the first writing system. However, the Maya civilization, flourishing between 250 CE and 900 CE, is famously known for its hieroglyphic script found on walls, pottery, and codices made from tree bark. Thus, the answer to which cultures developed the first writing on walls would be closer to the Mayans among the options provided.
While the Romans did have their writings, the script was not a form of early wall writing like that of the Mayans. The Romans' usage of writing on walls was not foundational but rather part of a much later period in history, characterized by inscriptions and public notices.