In medieval times, people preferred the royal courts over others because a.the royal courts tended ...

In medieval times, people preferred the royal courts over others because
a.   the royal courts tended to use trial by jury whereas others were still using trial by ordeal and trial by battle.
b.   the royal courts tended to use trial by ordeal and trial by battle while the others were still using trial by jury
c.   the ecclesiastical courts where using trial by jury whereas the royal courts where using trial by ordeal and trial by battle.
d.   the royal courts were guided by local customs, religious teachings, and trial by ordeal.