Final answer:
The anatomical plane of reference shown is the midsagittal plane.
Step-by-step explanation:
The term used to refer to the anatomical plane of reference shown is midsagittal plane (option b).
A midsagittal plane divides the body exactly in the middle, making two equal right and left halves. This plane is also known as the median plane.
For example, if you imagine dividing a human body into equally sized right and left halves, the plane passing through the nose and the navel would be the midsagittal plane.