A:
He should discontinue his Salah and join the congregation, as offering Salah congregationally is a Wajib (obligatory) unless one has an excuse. In this case, he does not have an excuse, because he is able to join them. There is no harm in discontinuing an obligatory Salah for a legitimate reason, and there is no doubt that joining the congregational Salah is a valid excuse. (Part No. 7; Page No. 421) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.