Q: In this task, you will be given sentences in which your task is to recognize the name of the organ of the body. An organ is a collection of tissues that structurally form a functional unit specialized to perform a particular function. Although there might be several correct answers, you need to write one of them.
 ( B ) Real - time PCR was performed on total RNA samples from the human brain regions known to express MOR1 .
A:
brain