Final answer:
The price of a large pizza with 2 toppings is $20.
Step-by-step explanation:
The function p(t) = 15 + 2.5t represents the price of a large pizza based on the number of toppings, t, ordered on the pizza. To find the meaning of p(2), we substitute 2 for t in the function and solve for p: 
p(2) = 15 + 2.5(2) 
p(2) = 15 + 5 
p(2) = 20
Therefore, the best interpretation of p(2) is that the price of a large pizza with 2 toppings is $20.