XIAOBAITU, pJIANG AND OTHER Experts: should I apply OPT or EAD b

Hi Expert,

I am F-1 student and need to get work authorization soon. Also my I-140 was approved and I-485 is still pending. Someone says I can still apply for OPT based on well-maintained F-1, this way it reduces the risk for the pending I-485. Others mention it is best to apply for EAD because OPT application may be risky based on I-485 application. Since I have never applied for EAD based on I-485, Can the OPT reviewer find out my I-485 application and what is the possibility of getting OPT approved? If the OPT is denied, can I switch to EAD based on I-485 later? is there any adverse effect that a denied OPT may have on the pending I-485?

Many thanks