The ancient Mesopotamian system of writing is referred to as

Hieroglyphics is the writing system used by ancient Egyptians, featuring pictorial symbols rather than the wedge-shaped characters of cuneiform. While both systems are early forms of writing, they originated in different cultures and served distinct purposes, making hieroglyphics incorrect in the context of Mesopotamian writing.

Linear A is an undeciphered writing system used by the Minoans on the island of Crete, not by the Mesopotamians. It is distinct from cuneiform in both form and function, as it is primarily associated with the Aegean civilization rather than the civilizations of ancient Mesopotamia.

Indo-European refers to a family of languages rather than a writing system. While some ancient Mesopotamian texts may have been written in languages that are part of the Indo-European family, this term does not describe any specific writing system, making it an incorrect answer to the question.

Similar to Indo-European, Altaic is a proposed language family that includes various languages spoken across Central Asia and parts of Eastern Europe. It does not pertain to a writing system and is unrelated to the ancient Mesopotamian context, rendering it an unsuitable choice.