Data privacy means protecting individuals' personal information and ensuring that they have control over how their data is collected, stored, and shared.
It focuses on giving individuals the right to know what data is collected about them and how it will be used.
Option (A) correctly defines this concept because it highlights individual control and consent.
Option (B) talks about collecting data for marketing, which is not about privacy protection.
Option (C) describes the opposite of privacy — unrestricted sharing reduces privacy.
Option (D) is about using data without consent, which violates privacy principles.
Therefore, the right answer is option (A).