Final answer:
The Alexiad was written by Anna Comnena, the daughter of Byzantine Emperor Alexios I Komnenos, and it is an important historical document detailing her father's reign.
Step-by-step explanation:
The Alexiad was written by Anna Comnena, the daughter of Byzantine Emperor Alexios I Komnenos. It is a comprehensive history of her father's reign and the events surrounding it, offering a unique perspective on the Byzantine Empire's politics, military affairs, and culture during this period. Anna's work is considered one of the most important primary sources of Byzantine history in the eleventh century and provides insight into the Crusades from the Byzantine viewpoint. Therefore, the correct answer to who wrote the Alexiad is 1) Anna Comnena.