单选题 An investor currently has a portfolio valued at $700,000. The investor’s objective is long-term growth, but the investor will need $30,000 by the end of the year to pay her son’s college tuition and another $10,000 by year-end for her annual vacation. The investor is considering four alternative portfolios: 　　Portfolio Expected Return Standard Deviation of Returns 1．8% 10% 　　2．10% 13% 　　3．14% 22% 　　4．18% 35% 　　Using Roy’s safety-first criterion, which of the alternative portfolios minimizes the probability that the investor’s portfolio will have a value lower than $700,000 at year-end? ()