SQL assignment question lowest apple stock prices

-----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?

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.