The Fall Risk in Elderly Patients Taking a Hypnotic Medication

The fall risk in elderly patients taking a hypnotic medication is being evaluated in a retrospective case-control study.  The investigators report the following association between medication consumption and fall incidence over the subsequent week:
Unadjusted odds ratio:  1.40 (95% confidence interval:  1.2-1.6)
Odds ratio adjusted for age and gender:  1.34 (95% confidence interval:  1.1-1.5)
Odds ratio adjusted for age, gender, and handgrip strength:  1.12 (95% confidence interval:  0.8-1.4)
Which of the following is the best interpretation of the study results?

A) Age and gender are not significant predictors of fall occurrence
B) 40% of falls in the study population are associated with use of the medication
C) Frailty confounds the association between the medication and fall occurrence
D) The medication causes elderly patients to fall
E) The study is grossly underpowered to detect any meaningful difference