The real question here is does the function use the smallest array size or the largest. When in doubt, I assume lazy (and test). So B.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions Unofficial Forum Rules and Guidelines "Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
We were debating the same thing as crossrulz: whether it would put extra zeros in when the smaller array ran out, or clip the whole thing it down to the smaller array size. We had to test it to check!
I think this raises a broader question: do other functions also use the smallest array size? If so then you would be able to answer any similar question. For example, replace "Interleave 1D Array" with the "Add" function and the same thing happens.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions Unofficial Forum Rules and Guidelines "Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
I had to look it up again in the help. The resulting array has the size of the smallest size array multiplied by the number of the input arrays. Brrr... You just have to know those kind of detail...