Analyze the relationship between 'Batman' and 'Justice League' within the context of the input sentence.
Options: employer, member of, industry, chief executive officer

Some of his most noteworthy projects include “Good Will Hunting,” “Pearl Harbor,” “The Town,” “Argo,” “Gone Baby Gone” and “Gone Girl.” Affleck is also slated to take on the role of Batman in the four upcoming films, “Batman v. Superman: Dawn of Justice,” “Suicide Squad,” “The Justice League Part One” and “The Justice League Part Two.” Jennifer Garner Net Worth: $60 Million
member of