Explanation:

Then can refer to different times depending on the context in which it is used. In this particular question, the correct answer is option 'C' which refers to the evening. Let's explore why this is the correct answer.

Context:
The context of the question is not provided, but we can assume that it is referring to a general time frame when the word "then" is commonly used.

Definition:
"Then" is an adverb that can indicate a specific time or a sequence of events. It is often used to refer to a time that follows or comes after another time or event.

Explanation:
In the given options, "morning" refers to the early part of the day, usually from sunrise until noon. "Afternoon" refers to the middle part of the day, usually from noon until around 5 or 6 pm. "Evening" refers to the time after sunset until bedtime, typically starting around 6 or 7 pm. "Night" refers to the period of darkness when people typically sleep.

When we consider the common usage of "then," it is often used to refer to events or actions that occur after a certain point in time. Evening is a time of day that comes after the afternoon and before the night. Therefore, if someone says "I will see you then," they are likely referring to meeting or seeing you in the evening.

Conclusion:
In conclusion, the word "then" can refer to various times depending on the context, but in this specific question, the correct answer is option 'C' which refers to the evening. It is important to consider the context and usage of the word to determine the appropriate time it is referring to.