Write SQL query to solve given problem: Among the easiest courses, what is the name of the course where most students got an A?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.name FROM registration AS T1 INNER JOIN course AS T2 ON T1.course_id = T2.course_id WHERE T1.grade = 'A' AND T2.diff = 1 GROUP BY T2.name ORDER BY COUNT(T1.student_id) DESC LIMIT 1