This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Definitions & Concepts, Subject name: Social & Preventive Medicine
If 10 women use IUCD for 10 years and assuming the failure rate of IUCD at 2/HWY, the number of expected accidental pregnancies would be- 
Select and explain. 
A. 1, B. 2, C. 5, D. 20
B: 2
Answer: B: 2 
Explanation: - Given PI=2 ; Time =10 x 12 =120 months ; No. of women = 10 - Number of expected accidental pregnancies = Pearl Index X Time X No. of women / 1200 = 2 x 120 x 10 / 1200 = 2