[Solved] A characteristic of development of Deuterostomia is A)spiral cleavage. B)mosaic development. C)the mesoderm developing from a special blastomere called the 4d cell. D)radial cleavage. Proper Objective: An aim or goal that is suitable and appropriately targeted for a specific task or endeavor. Optical Microscopes: Instruments that use visible light and a system of lenses to magnify small objects, allowing for the observation of details not visible to the naked eye. Physicians' Office Laboratories: Labs located within a physician's office where various tests are performed on clinical specimens to obtain information about the health of a patient. Objectives: The set of magnifying lenses contained in the nosepiece of a compound microscope.