In which anatomical plane does the "sagittal" divide the body?

The sagittal plane is an anatomical plane that divides the body into left and right portions. This plane runs vertically and can be described as a vertical line running from the front to the back of the body. Specifically, the midsagittal plane refers to the cut that divides the body into equal left and right halves. When animals are examined or described, understanding this division is crucial for assessing the symmetry and orientation of their physical structure.

The other choices refer to different anatomical planes: the upper and lower portions relate to the transverse plane, while the front and back portions refer to the frontal (coronal) plane. The terms medial and lateral describe relative positions within the same limb or body part and are not specific to a particular anatomical plane. Therefore, B is the correct option, accurately representing the function of the sagittal plane.