Confused by answer to quiz for Build, Operation, and Organisation

For question #1 “Why are changes that affect both the legacy system and the microservices difficult to implement?”
I don’t understand why one of the answers is C) “That entails deploying the microservices which takes considerable effort”
One of the big advantages of microservices is that deployment takes less effort. I can see the argument, from the top of the lesson, that deploying all microservices in a complex environment is more difficult, but the question doesn’t make that distinction.