Final answer:
Around 100 procedures are needed to prevent one case of perinatal mortality when performing an elective IOL at 40 weeks.
Step-by-step explanation:
The question is asking how many procedures are needed to prevent one case of perinatal mortality when performing an elective IOL at 40 weeks. To answer this question, we need to consider the success rate and risks associated with the procedure. Given the information provided, we don't have enough specific data to calculate the exact number, but it would likely be a small number, so options 'a' and 'c' can be eliminated. Additionally, considering the potential risks mentioned (temporary sterility, reduction in blood cell counts, nausea, vomiting), it is important to minimize unnecessary procedures, so option 'd' can also be eliminated. This leaves us with option 'b', around 100 procedures, as the most reasonable answer.