Answer:
The relationship is exponential, and the number of fleas increases by a factor of 3 per day.
Explanation:
Given :A dog begins his stay at the kennel with 25 fleas. Each day, the number of fleas triples.
Solution:
Let x denotes the number of days
Initial number of fleas = 25
Each day, the number of fleas triples.
The given situation represents the exponential function
General form=

where a is the initial amount and b is the rate factor
So, a = 25
b =3
So, function :

Thus Option B is correct.
Hence The relationship is exponential, and the number of fleas increases by a factor of 3 per day.