The correct sentence is (D) "I am senior to you."

Explanation:

• (A) "I am the seniorest to you." is incorrect. The correct superlative form should be "I am the most senior to you."

• (B) "I am more senior than you." is incorrect. The use of "more" is typically reserved for comparisons involving two items, not when indicating the highest degree.

• (C) I am the most senior to you: This is incorrect because "most senior" only makes sense when comparing three or more people. If you're just comparing yourself to one person, you should use "more senior."

• (D) "I am senior to you." is a concise and correct way to express the idea that one person is senior to another.

• E) I am as senior than you: This is incorrect because "as" is used for equality, not comparison. You should use "as senior as" to indicate equal seniority.