What are the two serving sizes of pancakes available at IHOP?

At IHOP, the correct terminology used to describe their two serving sizes of pancakes is "full stack" or "short stack." A full stack typically consists of a larger number of pancakes, making it ideal for those with a bigger appetite or for sharing, while a short stack is a smaller portion, often catering to those looking for a lighter meal or a quick snack.

This naming convention is well-known and aligns with how many breakfast establishments categorize their pancake offerings, ensuring that customers understand exactly how many pancakes they will receive with each order. The other choices listed do not accurately reflect the terminology used at IHOP, which is why they do not fit as the correct answer.