Universal Containers is preparing to implement Sales Cloud and would like its users to have Read Only access to an Accou

[answerhappygod]

Universal Containers is preparing to implement Sales Cloud and would like its users to have Read Only access to an Account record if they have access to its child Opportunity record.
How would a data architect implement this sharing requirement between objects?

A. Implicit sharing will automatically handle this with standard functionality.
B. Create an owner-based sharing rule.
C. Add appropriate users to the Account team.
D. Create a criteria-based sharing rule.