Correct Answer: Light : Dark

Solution : Given:

Hot : Cold :: ?

The relationship is that hot is the opposite of cold . They are antonyms representing opposite temperature conditions.

Now, let's apply the same logic to all the options of the analogy:

Option first: Summer : Sun

The relationship here is that "summer" is associated with or characterized by the presence of the "sun." Summer is a season known for its warm and sunny weather. This analogy represents a relationship where one term is associated with or characteristic of the other.

Option second: Germs : Disease

The relationship here is that "germs" can cause or lead to "disease." Germs are microorganisms that can cause various diseases. This analogy represents a causal relationship where one term leads to the other.

Option third: Light : Dark

The relationship here is that "light" and "dark" are antonyms, representing opposite states of illumination or the presence/absence of light. This analogy follows the pattern of antonyms.

Option fourth: Thin : Big

The "Thin : Big" analogy does involve antonyms, but it may not follow the exact same pattern as "Hot : Cold" because they refer to different attributes. "Hot" and "Cold" both pertain to temperature, while "Thin" and "Big" relate to size or dimension.

So, the related word for "Hot : Cold" is "Light : Dark".

Hence, option third is correct.