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System Design Quiz Practice
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Question 1 of 1
hard
System Design
How does an Idempotency Key protect users from being charged twice if their Wi-Fi drops during checkout?
A
It refunds the order automatically after 10 minutes
B
The payment gateway stores the unique UUID token; retried requests with the same token return the original receipt instead of charging the card again
C
It changes the user's password
D
It forces the payment to execute in cash
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