Answer:
a. a pyroclastic flow (nuée ardente)
Explanation:
A shield volcano is composed of entirely of thin lava flows that built up over a central vent.Shield volcanoes have very little pyroclastic material in them there is some amount of pyroclastic material present in the eruptive vents.All the other things that are :- pahoehoe lava ,a’a’ lava ,small deposits of ash fall can be seen most likely in the eruption of shield volcano and least likely seen is the pyroclastic flow.