Answer: Hence, option 'C' is correct.
Step-by-step explanation:
Since we have given that
A deli sells 2 hot dogs for $2.50
i.e.
Cost of 2 hot dogs = $2.50
And we need to find the constant of proportionality of dollars per hot dog, for which we'll use unitary method.
So,
Cost of 1 hot dog is given by

So, Cost of per hot dog is $1.25.
Hence, option 'C' is correct.