Final answer:
Refusing beta blocker medication for 2 days could be the possible reason for the change in blood pressure.
Step-by-step explanation:
A possible reason for the change in blood pressure from a trend of 160/90 to a current reading of 120/70 could be that the client has been refusing their beta blocker medication for 2 days (option B). Beta blockers are a type of medication that can help lower blood pressure. By not taking the medication, the client's blood pressure may have increased. This can explain the decrease in blood pressure when compared to the higher readings.