One of the Interventions for a Client with a Nursing

One of the interventions for a client with a nursing diagnosis of "Impaired swallowing is to position the client upright in a chair (60 to 90 degrees) during feeding times". The modifier in this intervention is which of the following?

A) Impaired swallowing.
B) Upright in a chair.
C) 60 to 90 degrees during feeding times.
D) Position in chair.