SQL assignment question lowest apple stock prices

OneLearn Course SQL
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#1

-----4) What was Apple’s lowest stock price (at the time of this data collection)?

for the above question do we need to check for lowest of all prices/ columns i.e. open, high, low, close or on just one column?
If just one column, which one??
if lowest of all column, how to do that. Pls provide hint?

#2

The hint is that every day has a low stock price value mentioned in low column.

You can use this column to find the minimum price of stock.