Which of the following is an indicator for children who are prepared to enter kindergarten?

A) Children who are can concentrate and focus
B) Children who can count to 25
C) Children who can recite the ABC song
D) Children who are ready for invented spelling

The ability to concentrate and focus is an important indicator of kindergarten readiness as it allows for engagement in learning activities and following classroom routines. While counting and reciting the alphabet are important skills, they may not necessarily indicate overall readiness for kindergarten. The use of invented spelling is also not necessarily an indicator of readiness, as it is a developmental process that emerges over time.