Question

In the diagram, which multicell structure is diploid (2n) (see attachment)

Answer 1

Though I don't know much about fungal biology, I'd be willing to bet the zygote is diploid, as in humans, since it is the product of the fusion of two haploid nuclei (the gametes).

Answer 2

Actually let me revise that answer - in humans, a zygote technically only refers to the first cell produced after fertilization. It is then called a morula upon further divisions, but is usually still referred to as a zygote for several cell divisions. Not sure if this transfers over to fungi as well.

A quick Wikipedia search tells me that the sporocyte is probably the answer they're looking for, as it is both multicellular and diploid.