Final answer:
The correct expression that represents how much Jack pays in total for the pony is Choice D: 5/4p.
Step-by-step explanation:
The correct expression that represents how much Jack pays in total for the pony is Choice D: 5/4p.
To find the total amount Jack pays, Jack needs to add the price of the pony to the 25% diamond pony tax. Since the tax is a percentage of the price, the correct expression is P + (0.25 × P), which simplifies to 1.25P or 5/4P.