5 Tall Tasks for Apple’s New C.E.O.

Apple said this week that Tim Cook, its chief executive since 2011, would step down and become its executive chairman in September. John Ternus, the company’s head of hardware engineering, will succeed Mr. Cook in the corner office.Mr. Ternus, who has worked at Apple for 25 years, will take over a moneymaking behemoth facing a series of pressing questions, including geopolitical threats, an unpredictable man in…