Magnetic resonance imaging (MRI) -- a noninvasive diagnostic procedure -- can be used to identify blockages in the coronary arteries. In contrast to angiograms -- the invasive procedure customarily used -- MRI's pose no risk to patients. Thus, to guarantee patient safety in the attempt to diagnose arterial blockages. MRI's should replace angiograms in all attempts at diagnosing coronary blockages.
which of the following, if true, would most support the recommentdation above?
(B)MRI's were designed primarily in order to diagnose blockages in the coronary arteries (D)An MRI is just as likely as an angiogram to identify an arterial blockage
答案是D，我没想明白，既然an MRI as likely as an angiogram, 又怎么会支持文中结论：replace angiograms呢？所以我认为答案是B，然否？ | 
