List the parameters of BP for diagnosing HTN? Difference between essential and secondary BP?

a) Systolic <120, Diastolic <80; Essential is idiopathic, Secondary has an identifiable cause
b) Systolic <140, Diastolic <90; Essential is reversible, Secondary is chronic
c) Systolic >130, Diastolic >80; Essential has no underlying cause, Secondary has a specific cause
d) Systolic >160, Diastolic >100; Essential is acute, Secondary is chronic