Us citizens participate in the judicial branch of government by
voting for senators.
voting for the president.
creating laws.
serving on juries.

Serving on juries. It is this answer because the branch is all about the court and to serve on a jury means to participate in court. Creating laws is a duty which belongs to the legislative branch. The president belongs to the Executive branch. I do not remember what the senators belong to but it’s not the judicial.

D. US citizens participate in the judicial branch of government by serving on juries :)