Q. Consider the following statements:
1.Interoperability is the technical compatibility that enables a payment system to be used in conjunction with other payment systems.
2.In QR codes, the black squares represent the background, while the white squares contain encoded information.
3.Interoperability of UPI with the digital rupee means all UPI QR codes are compatible with Central Bank Digital Currency (CBDC) apps. 
Which of the statements given above are correct?

[A] 1 and 2 only

[B] 2 and 3 only

[C] 1 and 3 only

[D] 1, 2 and 3

Answer: C
Notes:

Explanation –

Statements 1 and 3 are correct. Interoperability is the technical compatibility that enables a payment system to be used in conjunction with other payment systems. Interoperability of UPI with the digital rupee means all UPI QR codes are compatible with CBDC apps.

Statement 2 is incorrect. In QR codes, the black squares represent the encoded information, while the white squares make up the background.

Source: ForumIAS