Final answer:
A. Fear. Grendal's primary emotion upon hearing the blind musician in the passage from page 44 of Grendal is fear.
Step-by-step explanation:
In the passage from page 44 of Grendal, the primary emotion or reaction of Grendal upon hearing the blind musician can be described as fear. This can be inferred from the text which states, 'The serpentine wind whipped around me. I felt horror rise in my stomach.' The use of words such as 'horror' and 'fear' indicate Grendal's strong negative emotional response towards the musician. This fear could be a result of Grendal perceiving the musician as a potential threat or danger.