Final answer:
Emperor Justinian I strengthened and expanded the Byzantine Empire through territorial expansion, monumental building projects, codification of Roman law, and religious consolidation.
Step-by-step explanation:
The statement that correctly describes Justinian's impact on the Byzantine Empire is a) Strengthened and Expanded. Emperor Justinian I's reign was marked by significant achievements, including the expansion of the empire's boundaries to its largest geographical area, monumental building projects like the Hagia Sophia, codification of Roman law, and the reconquest of parts of the Roman West.
His efforts to suppress the Arian belief and the consolidation of religious and political power illustrate the strengthening of imperial control and expansion of the empire's influence. However, these endeavors were extremely costly, and the empire faced challenges after his death due to the enormous expenses of his campaigns and ongoing conflicts with the Persians.