Final answer:
Among the given options, C. Systolic 143mmHg is considered a positive risk factor for atherosclerotic cardiovascular disease as it represents elevated blood pressure, which is a known risk factor.
Step-by-step explanation:
The positive risk factor for atherosclerotic cardiovascular disease among the choices is C. Systolic 143mmHg, which indicates elevated blood pressure, a known risk factor for cardiovascular disease.
Looking at the options given, HDL (high-density lipoprotein) levels of 66mg/dL (A) are considered protective against heart disease, as HDL is known as the "good cholesterol transporter". A serum cholesterol level of 195mg/dL (B) is below the 200 mg/dL threshold that is considered desirable for total blood cholesterol. A BMI (body mass index) of 28kg/m2 (D) is considered overweight but does not alone constitute a high-risk factor unless accompanied by other issues like high LDL, low HDL, hypertension, or diabetes.
Hypertension is defined as a blood pressure persistently at or above 140/90 mm Hg. Therefore, a systolic pressure of 143 mm Hg is a precursor to hypertension, which is one of the conditions that lead to most cases of cardiovascular disease by putting the cardiovascular system under strain.