Choose the possessive adjective that can be modify to match gender and number. vuestro mis mi su

The correct answer is:  [A]:  "vuestro" .

Since: "vuestro"; can match number and gender;  
 (e.g. "vuestro" ; "vuestros"; "vuestra", "vuestras" ;

whereas the other answer choices given: 

"mis", "mi", "su";  can only match number —(not 'gender').

Um basically write about the event u studied and describe using the what is required