A Research Is Being Done to Evaluate the Efficacy of Beta-Blocker

A research is being done to evaluate the efficacy of beta-blocker medication in patients suffering from acute myocardial infarction (MI) . The study discovered that 20 individuals out of 90 who used a beta-blocker in the week preceding a MI experienced a severe arrhythmia incident while hospitalized. The study also discovered that 30 of the 70 individuals who did not use a beta-blocker suffered a severe arrhythmia. What was the chances ratio of getting significant arrhythmia in individuals who used beta-blockers against those who did not?

A) (20 × 30) / (70 × 40)
B) (20 × 40) / (70 × 30)
C) (20 × 70) / (30 × 40)
D) (20 / 50) / (70 / 110)
E) (20 / 90) / (30 / 70)