Read the text and determine if the sentence is true (see options at the end):

How to make acidophilus yogurt<br>Combine 4 cups (950ml) of milk and 3/4 cups (120 g) of powdered milk (if not using whole milk) in the saucepan. Set the burner to medium heat and place the saucepan on the burner. Whisk the mixture constantly to keep it from sticking to the pan.

Sentence: The liquid that comes out of cows utters are not necessary.

+ Yes.
+ It's impossible to say.
+ No.
No