Which of the Following Is an Example of Heterogeneity of Services

Which of the following is an example of heterogeneity of services?

A) The packaging of the pizza that I ordered today had a very different design and was made of recyclable paper.
B) The tire I bought at a Chicago service station came with a discount but lasted as long as another other tire.
C) The customer service agent who contacted me last week was more helpful than the one who contacted me today.
D) The surgical instruments that doctors use in a New York hospital are the same as those used by doctors in the Miami hospital where I was examined.