Read the text below and identify the cause for the event mentioned.
"Due to heavy rainfall overnight, the school's main sports field was completely flooded. This meant that the much-anticipated inter-class football tournament, scheduled for Wednesday afternoon, had to be postponed. The principal announced that the tournament would now take place next Friday, once the field had dried out and was safe for play."
A) Students were not ready for the match.
B) The school principal set a different date.
C) The sports field was flooded due to heavy rainfall overnight.
D) There was a risk of players getting injured.
E) The tournament was wanted to be held on a safer date.