Final answer:
Charles I was elected as Holy Roman Emperor Charles V by seven prince-electors, as established by the Golden Bull.
Step-by-step explanation:
Charles I became Holy Roman Emperor Charles V through an election process. This is evident from the historical context provided by the Golden Bull, which clarified that the selection of a new Holy Roman Emperor would be done by seven princes known as electors. Indeed, Charles I, after the death of his grandfather Maximilian I, was elected to become Charles V, signifying that the choice of emperor was determined by a form of election rather than divine right or outright purchase.
While the concept of divine right was a prevalent justification for monarchical rule, and it is true that rulers often tried to exert influence over the selection of church officials and secure the church's support for their rule, the Holy Roman Emperor was selected by electors, as exemplified by the precedent established by the Golden Bull. Purchasing votes, though not impossible in historical context, was not the primary means by which Charles I ascended to the imperial throne of the Holy Roman Empire.