According to 10 days role, the safest time for female to have X-ray examination of pelvic region

According to 10 days role, the safest time for female to have X-ray examination of pelvic region is:
A- 10 days before beginning of menses
B- 10 days after beginning of menses
C- 1st 10 days of month
D- Last 10 days of month
E- All are wrong