Answer:
The third option wednesday.
Explanation:
on friday it was -4 c. aass the temperature grow in minuses(negatives) it becomes colder. just add 4 and 9 because it tells you that it was colder by nine celsius. higher negative number means lower(colder) temperature. 4+9=13. now add minus to the number we get -13. if you look at the chart this temperature was reported on wednesday. hope i was able to help. ask if need help any further.