Lawrence Craven, a doctor from the USA, is the author of several published reports, one of which introduced the idea in 1953 ________ aspirin could reduce the risk of heart attacks by thinning blood.

Lawrence Craven, a doctor from the USA, is the author of several published reports, one of ________ introduced the idea in 1953 _________ aspirin could reduce the risk of heart attacks.

 Lawrence Craven, a doctor from the USA, is the author of several published reports, one of which introduced the idea in 1953 ________ aspirin could reduce the risk of heart attacks by thinning blood.

A．when            B．where            C．that              D．which

Lawrence Craven,a doctor from the USA,is the author of several published reports,one of     ________introduced the idea in 1953      aspirin could reduce the risk of heart attacks.

Lawrence Craven, a doctor from the USA, is the author of several published reports, one of _______ introduced the idea in 1953 _______ aspirin could reduce the risk of heart attacks.

A. them; when               B. which; that            C. what; that      D. which; when