PAMHO AGTSP!!
The answer to this question is quite important, there is only one qualified guru/acharya and that is Sirla Prabhupada! We are supposed to be his desciples, and follow what he said. Just before Srila prabhupada left this world he said, "there is no need to change anything", therefore we can see Srila Prabhupada is to remain Jagad Guru! So the answer to the question who is sri Guru? Srila Prabhupada!!! Hope this information helps!!!
Your servant...
Haribhajan