The correct option is A 5
Let's fill the first box with 5 matches.
Remaining number of matches = 25 - 5 = 20
Let's fill the second box with 5 matches.
Remaining number of matches = 20 - 5 = 15
On filling the third box with 5 matches, we get
remaining matches = 15 - 5 = 10
On filling the fourth box, we get
remaining matches = 10 - 5 = 5
Lastly, we fill the last 5 matches in the fifth box to get
remaining matches = 5 - 5 = 0
So, there are 5 full boxes of matches.