Answer- DTretinoin plus concurrent anthracycline-based (i.e., idarubicin or daunorubicin) chemotherapy appears to be among The most effective treatment for APL. leading to CR rates of 90-95%Arsenic trioxide has significant antileukemic activity and is being explored as pa of initial treatment in clinical trials of APL. Arsenic trioxide increases the risk of APL differentiation syndrome & may prolong the QT interval.As of 2013 the standard of treatment for concurrent chemotherapy has become arsenic trioxide, which combined with ATRA is referred to ATRA-ATO.Before 2013 the standard of treatment was anthracycline (e.g.daunorubicin, doxorubicin, idarubicin or mitoxantrone)-based chemotherapy.Side effect of ATRA therapy as dyspnea, fever, weight gain, peripheral edema and is treated with dexamethasone.