You need not come unless you want to.

The original sentence "You need not come unless you want to" is a valid construction, but it can be more clearly expressed. The corrected sentence is: You don't need to come unless you want to. Here’s why:

Clarity:
The phrase "You don't need to come unless you want to" provides a clearer and more straightforward expression of the same idea. It avoids the more formal or archaic "need not" and uses modern, conversational language.

Options B, C, and D:
These options do not accurately convey the original meaning of the sentence. They introduce unnecessary complexity or incorrect logical relationships.

Option E:
Although the original sentence is grammatically correct, Option A is preferred for its clarity and simplicity in modern English.

Thus, the most appropriate and clear option is You don't need to come unless you want to.