A young infant may be feeding entirely on mother's milk, which is white in colour but the stools, which the infant passes out are quite yellowish. What is this yellow colour due to?
1. Intestinal juice
2. Bile pigments passed through bile juice
3. Undigested milk protein casein
4. Pancreatic juice poured into duodenum

Assertion: In humans none of the lipases act in an acidic pH.
Reason: All lipases require bile salts for their activation.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.