Final answer:
The Sumerian belief system describes the afterlife as 'grim,' a place of eternal sorrow and despair. The gods of Mesopotamia are best described as 'fickle' and 'easily angered,' necessitating careful worship by the Sumerians.
Step-by-step explanation:
The adjective that best describes the afterlife according to the Sumerian belief system is 'grim'. In Sumerian religion, after death, all people were thought to spend eternity in a bleak underworld sometimes referred to as "the land of no return." This place was characterized as gloomy and frightening, where the dead resided in extreme sorrow, consumed by regret and despair, eating dust and longing in vain to return to the world of the living. This portrays a very pessimistic view of the afterlife, indicating that the correct answer is a. grim.
The two adjectives that best describe the gods of Mesopotamia are 'fickle' and 'easily angered'. These characteristics reflect the unpredictable and often harsh responses of the gods to human actions, which necessitated constant efforts by the Sumerians to honor and appease the deities to avoid their wrath.