How to calculate CEO's stock option's BS value

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Anybody has this kind of experience? I'm currently tryting to match my calcualtion with the WRDS calculation of BS value, however, there are always 10 percent difference between those. I think the problem may come from the volatility and dividiend I used. I'm not sure whether do I need to adjust it to 5% and 95% when calculate B&S value.

Any body can help me out? I would deeply appreciate it.