prevent 1 fracture over 12 months? - proteus

[ArchivalUser]

Medication X is being studied for its efficacy in reducing fractures in elderly women. A double-blinded placebo controlled study is conducted over 12 months. 100 women aged 67 are allocated to the treatment group and are given medication X over the 12 month time period. 100 women aged 67 are allocated to the control group and receive placebo for 12 months. Over the 12 months, 5 fractures were found in the treatment group compared to 15 fractures in the control group. What number of 67-year-old women would need to be treated with medication X to prevent 1 fracture over 12 months?

A. 1
B. 5
C. 10
D. 50
E. 60