Final answer:
The correct measurement of beam intensity used to describe levels of intensity associated with US bioeffects is Spatial Peak Temporal Average.
Step-by-step explanation:
The measurement of beam intensity used to describe levels of intensity associated with US bioeffects is Spatial Peak Temporal Average (D). This measurement takes into account the highest beam intensity occurring in space at a given moment (spatial peak) and averages it over the duration of the pulse (temporal average). It is critical for assessing the potential biological effects of ultrasound as it appropriately quantifies the exposure in a way that reflects the potential for heating and other bioeffects in tissues.