What is a disadvantage of using QR codes?

The reasoning behind choosing that particular answer lies in the requirement for specific technology to utilize QR codes effectively. QR codes are designed to be scanned using a camera-equipped device, typically a smartphone or tablet, which must also have the necessary software or application installed to interpret the code. This can pose a limitation for users who do not possess such devices or the appropriate applications, making the potential accessibility of QR codes a challenge.

Options that discuss the inherent characteristics of QR codes, like their ability to be scanned from various angles or their data capacity, do not reflect disadvantages. In fact, the ability to scan from any angle is a benefit as it increases ease of use. Meanwhile, the claim of infinite data capacity overstates what QR codes can actually store, as they do have a maximum limit. Similarly, stating that QR codes are slower than barcode scanning does not represent a universal truth; speed can depend on various factors such as the scanning technology used and the complexity of the data encoded. Thus, the need for specific hardware and software stands out as a tangible downside unique to QR codes.