Volume, SM-Bank 103 MC

Carrie has a small container of milk.

It contains 250 millilitres of milk.
 

Carrie buys a pack of 6 of these milk containers.

How many litres of milk are in the pack?

1. 0.25 litres
2. 1.5 litres
3. 2.5 litres
4. 15 litres