What is the MAIN reason GDPR Article 4(22) establishes the concept of the “concerned supervisory authority”?

What is the MAIN reason GDPR Article 4(22) establishes the concept of the “concerned supervisory authority”?
A . To encourage the consistency of local data processing activity.
B . To give corporations a choice about who their supervisory authority will be.
C . To ensure the GDPR covers controllers that do not have an establishment in the EU but have a representative in a member state.
D . To ensure that the interests of individuals residing outside the lead authority’s jurisdiction are represented.

Answer: D