$Tesla Motors(TSLA)$Elon Musk says he’s using a Twitter poll to determine the future of 10% of his Tesla sharesKEY POINTS-Elon Musk on Saturday asked his 62.5 million Twitter followers to determine the future of a chunk of his Tesla holdings.-Twitter polls are informal, however, and Musk previously said he was likely to sell “a huge block” of his options in the fourth quarter.Elon Musk on Saturday asked his 62.5 million Twitter followers to determine the future of a chunk of his Tesla holdings.Twitter polls are informal, however, and Musk previously said he was likely to sell “a huge block” of his options in the fourth quarter.At an appearance at the Code Conference in September, Musk said when his stock options expire at Tesla, his marginal tax rate