In today's storage media, "SD" does not mean single density, but the SD stands for secure digital. That's why you also say "SD card" for, logically, secure digital card. In English: "Secure Digital Memory Card".
The term "Single Density" originates from floppy discs and is also used only there. And single density means "simple density" or also called 1D.
The questioner is about quality, not about storage media. So your answer would be over the topic.
Is logical if HD stands for "high definition".
SD stands for standard definition and it has a lower resolution than HD
The answer is up.
Fun fact. The resolution at SD is "only" 720×576 pixels.
Single Density
What? No. No!
It used to be.
For storage media.
Single and high density.
DS
Double and single!
I'm just here for fun.
In today's storage media, "SD" does not mean single density, but the SD stands for secure digital. That's why you also say "SD card" for, logically, secure digital card. In English: "Secure Digital Memory Card".
The term "Single Density" originates from floppy discs and is also used only there. And single density means "simple density" or also called 1D.
The questioner is about quality, not about storage media.
So your answer would be over the topic.