BIRD : BEAK CUP : LIP

To find the alternative that replaces the question mark in the given analogy, we need to analyze the relationship between the words "BIRD" and "BEAK" and then apply the same logic to the second pair of words "CUP" and the missing word.

1. Understanding the Relationship between "BIRD" and "BEAK":
A beak is a characteristic feature or a body part of a bird. It is used for various functions such as eating, feeding young ones, and grooming. The beak is an essential and defining attribute of a bird.

2. Applying the Same Logic to "CUP" and the Missing Word:
To find the missing word that has a similar relationship with "CUP" as "BEAK" has with "BIRD", we need to look for a characteristic feature or a body part that is associated with a cup.

3. Analyzing the Options:
a) BUSH: A bush is not directly related to a cup. It does not have a similar relationship as a beak has with a bird.
b) FOREST: A forest is a natural habitat or an environment for various living organisms, but it does not have a direct relationship with a cup.
c) LIP: Lips are the characteristic feature or body part associated with a cup. Just like a beak is an essential attribute of a bird, lips are an important part of a cup. They provide a boundary and help in holding and drinking from a cup.
d) EYE: Eyes are not directly related to a cup. They do not have a similar relationship as a beak has with a bird.

4. Conclusion:
Based on the analysis, the alternative that will replace the question mark is option 'C' - LIP. Lips are the characteristic feature or body part associated with a cup, similar to how a beak is associated with a bird.