Final answer:
Dr. Arlan Fuhr option (d) developed the activator methods technique, a gentle chiropractic adjustment technique using a handheld instrument to restore motion in the spine.
Step-by-step explanation:
The activator methods technique was developed by Dr. Arlan Fuhr. This chiropractic technique uses a handheld adjusting instrument to deliver a gentle impulse force to the spine to restore motion to the targeted spinal vertebra or joint.
Unlike traditional manual forms of spinal manipulation, which involve twisting or cracking sounds, the activator method technique is known for being a softer and more precise adjustment technique. This method has been used by chiropractors since the late 1960s and is one of the most widely used approaches in chiropractic care today.