The presence of both plant impressions and phytoliths led researchers analyzing soil in and around Mesolithic graves in Israel to conclude there was habitual use of plants, and particularly of flowering and aromatic varieties, in the rituals associated with burial of the dead at Raqefet.
A.researchers
analyzing soil in and around Mesolithic graves in Israel to conclude there was habitual use of plants, and particularly of flowering and aromatic varieties, in the rituals associated with burial of the dead at Raqefet-analyzing is a verb+ing modifier that modifies researchers
B. researchers who
would analyze soil in and around Mesolithic graves in Israel to conclude there had been habitual use of plants, and particularly flowering and aromatic varieties, in the rituals in association with burial of the dead at Raqefet-would indicates imaginary condition
C. researchers who
had analyzed soil in and around Mesolithic graves in Israel
to conclude that in the rituals associated with burial of the dead in Raqafet, there had been habitual plant use, and particularly flowering and aromatic varieties-past perfect tense is not required here-simple past is enough
D. researchers,
analyzing soil in and around Mesolithic graves in Israel to conclude there was habitual use of plants in the rituals associated with burial of the dead at Raqefet, and particularly of flowering and aromatic varieties-verb+ing (analyzing) is modifing entire preceding clause and not researchers
E. researchers analyzing soil in and around Mesolithic graves in Israel
in concluding particularly flowering and aromatic varieties of plants were in habitual use in the rituals associated with burial of the dead at Raqefet - preposition "to" is preferred- to conclude
Ps:I am not sure my analysis is correct, check for expert review