The correct choice is A: "you’d better change".

Here's why:

1. "You’d better" is a fixed expression that means it is advisable or wise to do something.
2. The verb that follows "you’d better" should always be in its base form. In this case, "change" (the base form) is used correctly in option A.

The other options are not grammatically correct:

B. "you’d better changed" - "changed" is the past participle and is incorrect after "you’d better."
C. "you’ve better changed" - "you’ve" (you have) is not the correct form to use before "better."
D. "you will better change" - This construction does not correctly match the usage of “better” in advising someone.

So, the correct sentence is: "I think you’d better change the battery before going to Vienna."