As a tax consultant, advise employees of Alphabet Inc. on the tax implications of exercising stock options. Alphabet's employees were granted stock options with an exercise price of $100 per share when the market price was $150 per share. The current market price is $200 per share, and the employees are considering exercising their options. Calculate the tax consequences of exercising the stock options under both the incentive stock option (ISO) and non-qualified stock option (NSO) plans. Discuss the differences in taxation between ISOs and NSOs and provide recommendations for tax-efficient exercise strategies.