Final answer:
The meaning of the medical abbreviation 'D/C US in the area of R SI joint' is to discontinue ultrasound in the area of the right sacroiliac joint.
Step-by-step explanation:
The correct answer is a. Discontinue ultrasound in the area of the right sacroiliac joint. D/C is a medical abbreviation for 'discontinue' or 'discharge.' 'US' stands for 'ultrasound,' and 'R SI joint' refers to the right sacroiliac joint. Therefore, the phrase 'D/C US in the area of R SI joint' means to stop or cease ultrasound treatment in the area of the right sacroiliac joint.