Which statement about DB2 aggregate registry variables is true?

A.
An aggregate registry variable that is explicitly set by an application cannot be
overwritten.

B.
An aggregate registry variable overrides any corresponding explicitly set registry variable.

C.
A registry variable that is explicitly set by an application can only be overwritten by
aggregate registry variable.

D.
A registry variable that is implicitly configured through an aggregate registry variable may
also be explicitly defined.