Compared to stored analog data, what is a disadvantage of stored digital data?
A. Multiple copies of the stored data take up very little space.
B. They lose quality when they are copied several times.
O
C. Stored data are made up of only two different values.
D. They are vulnerable to hackers and viruses.

D

Explanation:

Let's analyze each option.

A "Multiple copies of the stored data take up very little space."

This is actually true, and it is a positive aspect, as stored digital data does not need any "physical space", it only needs memory and not a lot of it.

So storing data digitally is way more efficient than storing analog data.

B: "They lose quality when they are copied several times."

The data shouldn't change when it is copied, so you should not see a lose in quality.

C: "Stored data are made up of only two different values."

True, but as we know, we can define a lot of things with only two values (zeros and ones), so this is not really a disadvantage.

D: "They are vulnerable to hackers and viruses."

This is true, when you store your data digitally you become vulnerable to hackers stealing your data, so you need to get informatic security in order to protect your data. The same thing with viruses, if you have all your data stored in a given device, and the device becomes infected, there is a chance that you just lost all your data, so you need to have multiple backups of your important information, and again, some protection against viruses.

The correct option is D.