Change "Ann loves tennis" to the pronoun form.

The correct transformation is achieved by changing the subject "Ann" to the appropriate pronoun that corresponds to her gender. Since “Ann” is a female name, the pronoun needed here is “she.” Therefore, transforming the sentence “Ann loves tennis” into the pronoun form results in “She loves tennis.”

This choice maintains both the original meaning of the sentence and correct subject-verb agreement, making it not only contextually appropriate but also grammatically correct. Focusing on this structure ensures clarity while keeping the essence of the original statement intact.

The other options do not align correctly with the gender of the subject; "they" and "he" refer to groups or males, while "it" is usually used for objects or animals, not suitable for a person. Hence, these alternatives do not provide an accurate transformation of the original sentence.