Which of the following are specialized cells?

blood cells

muscle cells

bone cells

all of the above

The answer is all of the above.

Cells are all similar, but still, they differ in size, shape, function. All of this depends on their role in the body. A blood cell, muscle cell, bone cell, for example, are similar enough on some basic level. Still, each of these cells is specialized to work in the special way the body needs to. They are all specialized for different functions.