If in a group of students some weak as well as some intelligent students are included then which of the following practices is considered a better way for imparting education to each of the students?1. Keeping the standard of teaching high so that weak students also work hard to attain the level of intelligent students2. Keeping the standard of teaching at a low level so that each student of the class may understand the subject matter being explained by the teacher3. Keeping the standard of teaching at a medium level so that the intelligent students may maintain their interest in attending the classes.4. Arranging additional classes for the week students