which of these advances contributed to improving the legibility of lettering?

Graphic art evolved from ancient cave paintings created in prehistoric times. The term "ideogram" is used to describe writing systems that evolved from these forms, such as Egyptian hieroglyphs and Chinese characters. Chinese ideograms appeared as early as 8,000 years ago, and a complete writing system in Chinese characters was developed 3,500 years ago. Egyptian hieroglyphs were part of a writing system used by the ancient Egyptians. They contained alphabetic and ideographic elements. Many modern scripts of today can be traced back to the Greek alphabet. The Greek alphabet began with the adoption of Phoenician letters. Almost a hundred years later, the Romans adapted the Greek alphabet and used it as the basis for the uppercase alphabet that we use now. The Romans developed a formal script for important manuscripts and official documents, and a more informal style for routine types of writing. They also made another important contribution to type design. In their alphabet carvings on tablets, stonemasons added little hooks to the tips of letters to prevent their chisels from slipping. This helped create a very pleasing style that we call serifs.

A: The term "ideogram" is used to describe writing systems that evolved from these forms, such as Egyptian hieroglyphs and Chinese characters.
B: Egyptian hieroglyphs were part of a writing system used by the ancient Egyptians. They contained alphabetic and ideographic elements.
C: The Romans developed a formal script for important manuscripts and official documents, and a more informal style for routine types of writing.
D: They also made another important contribution to type design. In their alphabet carvings on tablets, stonemasons added little hooks to the tips of letters to prevent their chisels from slipping.​