How can you make sure the bean from extension A doesn’t override the one from extension B?

You are implementing two new independent extensions, extension A and extension B, both of which extend and overwrite a bean of the core platform.

How can you make sure the bean from extension A doesn’t override the one from extension B? Note: There are 2 correct answers to this question.
A . Use the beans’ parent attribute in extension B to specify the core bean.
B . Add only one of the extensions into localextensions.xml at the same time.
C . The beans are loaded in alphabetical order; therefore, extension B takes precedence.
D . Define a dependency wherein extension B requires extension A

Answer: B, D