The assertion and reason presented in the question refer to the human liver`s role in digestion, particularly fat digestion.

Option 1 suggests both the assertion (A) and the reason (R) are true, and that the reason is directly connected to the assertion. However, this is not correct. While the liver does play a significant role in fat digestion, this is facilitated by the production of bile, not fat-digesting enzymes as mentioned in the reason.

Option 2 also asserts that both (A) and (R) are true, but the reason is not the correct explanation for the assertion. Again, this option is incorrect as (R) is not a true statement.

Option 3 specifies that the assertion (A) is true while the reason (R) is false. This is the correct answer. The liver does play a major role in fat digestion through the production of bile, but not through the production of fat-digesting enzymes as stated in the reason.

Option 4 suggests that (A) is false and (R) is true, which would be incorrect as the liver does contribute to fat digestion, contradicting the false assertion.