Tesla Inc. is slated to report first-quarter earnings after the bell on Wednesday, with investors zeroing in on production in China and also worrying whether Chief Executive Elon Musk would divide his attention further with his bid for Twitter Inc. Tesla TSLA, -3.66% executives will host a conference call with analysts and others after the results at 5:30 p.m. Eastern. That call will be [webcast.] It is unclear if Musk, who roiled markets in recent days with a $43 billion buyout offer for the social-media company , would attend the conference call and take questions. Related: Twitter gave rise to...