Morris had extended the personality typology proposed by Friedman and Rosenman by suggesting which type of personality?

Type C

Friedman and Rosenman classified individuals into Type-A and Type-B personalities. They were trying to identify psychosocial risk factors when they discovered these types. People having Type-A personality  possess high motivation, lack patience, feel short of time, be in a great hurry, and feel like being always burdened with work. They find it difficult to slow down and relax. People with such personality are more susceptible to problems like hypertension and coronary heart disease (CHD). The risk of developing CHD with Type-A personality is sometimes even greater than the risks caused by high blood pressure, high cholesterol levels, or smoking. In contrast Type-B personality,  can be understood as the absence of Type-A traits. This typology of Friedman and Rosenman has been further extended. Morris has suggested a Type-C personality, which is prone to cancer and individuals characterised by this personality are cooperative, unassertive and patient, who suppress their negative emotions (like anger), and show compliance to authority.

Recently, a Type-D personality has been suggested, which is characterised by proneness to depression.