Helens was especially deadly, because a bunch of the

Mt. St. Helens was especially deadly, because a bunch of the eruption did not escape from the top vent but instead, from a side vent. This really surprised geologists, and cost one geologist his life.
Based on your learning from the video about Mt St Helens, there was a pre-existing condition that turned out to be responsible for the deadly lateral blast.
The following list of events all occurred at Mt. St. Helens. Some played a key part in the lateral blast and one is just an ordinary eruption event.
Which of the following in the chain of events is NOT specifically related to conditions preceding the lateral blast?
Select one:
a. melting of snow and heating of groundwater 
b. rising magma into the volcanic neck
c. 
d. hydrothermal weathering of volcanic rock
Select one:
a. Mt. Hood
b. Mt. Adams
c. Mt. Shasta
d. Lassen Peak  Lassen Peak was the last to erupt before Mt St Helens!
e. Mt. Rainier
f. Kilauea 
g. Mt. St. Helens
H0W MANY CALDERAS DOES Mt.St.HELENS HAVE ?
is it, 0,1,2 or 3 ?