I suppose it is not entirely unreasonable to make the interface of an online question similar to that of the respective paper question. I guess the main problem of such approach is that it imposes too many paper-like constraints on something that could otherwise be very flexible. The MC question seems (again) a case in point. So I've drafted a new MC qtype which takes an alternate approach.
The gist of the approach is that you can enter in one question many correct choices and many distractors and then tell the question how many of each to select randomly and display in the attempt.
The illustration demonstrates this for the classic 4 choice 1 correct mc (other avaiable methods are the multi and the multi all or nothing). Note in the question settings the number of correct set to 1 and number of distractors set to 3 (it is also possible tot let the question pick these numbers randomly in which case the number of choices may change from one attempt to another). The more items in each section the greater the variation.
Below the settings there is the corrects section with a few correct answers. In the one answer only method there is no need to set the fractions and they can remain on default.
Further below is the distractors section with a few distractors:
And then two attempts of the same mc single question display different sets of choices: