Final answer:
The ratio form of 2 1/2 is 5:2.
Step-by-step explanation:
A fraction can be written as a ratio, where the numerator represents the number of parts we have and the denominator represents the total number of equal parts. In this case, 2 1/2 can be written as 5/2. So the ratio form of 2 1/2 is 5:2, which is option b.