Answer: a.

Explanation:
Mice is the clear winner in a Google poll:
Computer mice: 319,000
Computer mouses: 30,600
(But that’s not why we say it’s correct.)

There’s a lot of discussion about this issue online and, although consensus seems to be for mice, some folks insist that mouses is more correct or even mouse, like the plural of moose (which is moose). Here’s a sample argument:

MOUSE is an acronym, and is short for Manually-Operated User-Selection Equipment so technically MOUSE is already the plural (… Equipments?) Most people, however pluralise acronyms, and initials in general, by adding a small s, so it would be MOUSEs, which seems a bit silly. Mice is also wrong, as it doesn’t stand for anything, but it does make more grammatical sense than calling them MOUSE or MOUSEs. (NB: If a MOUSE was so called because it looked like the animal, then mice would be correct, but that isn’t the case, although small body, long tail, who knows…)

We’re not sure about that acronym story. It seems to us more likely a backronym, made up with likely words to stand for the letters in the name. Because, after all, everything should be an acronym, right? (OT: Did you know there’s a sarcasm mark? Maybe I’ll go see if I can’t round one up.)

The OED lists the plural as mouses. Much as we hate to disagree with the OED, we will do so in this case.

Why do we say with such certainty that the plural of (computer) mouse is mice? We went to the source. In this video, at about 10:03, Douglas Engelbart, who invented the mouse, refers to it in the plural as mice. Oh, and by the way? He said the name was chosen for the device’s resemblance to its furry namesake — yes, small body, the long tail.Maybe the tendency to scamper…

So there you have the authorative answer: Douglas Englebart says the plural of mouse is mice. So it would just be silly for us to say it should be something else. Especially mouses.

Thanks to @OnewordTF for the idea!

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