The correct answer is: Amit is married to Sangeeta.
The preposition “to” is used to indicate a relationship between two people, such as marriage, friendship, or family. In this case, Amit is married to Sangeeta, which means that they are legally and/or emotionally bound together as husband and wife.
The other options are incorrect because they do not accurately describe the relationship between Amit and Sangeeta. The preposition “at” is used to indicate a location, while the preposition “between” is used to indicate a position or distance between two or more things. The preposition “with” is used to indicate a relationship between two or more people or things, but it does not specifically indicate a marriage or other romantic relationship.