Thanks Everyone...
IRCC has asked us to submit passport, photos along with Appendix B. There is a note "Please complete this form for yourself, your spouse/common-law partner, and your dependent children who will accompany you to Canada." on the Appendix B.
Now my question is that there is no dependent children of my parents and all of my siblings live in Canada. Therefore, my parents do not need to mention about their children info on the Appendix B form. This is my understanding. However, those who already submitted their passports, please confirm. I am excited now and I do not want to make any mistake at the eleventh hour.