Reasons for preference of internal jugular vein over external jugular  vein for measurement of JVP include all except: (A) IJV is in direct continuation with right atrium, (B) Increased sympathetic activity in IJV, (C) EJV passes through more facial planes, (D) Prominent valves at proximal portion of EJV
Answer is B. Increased sympathetic activity in EJV causes vasoconstriction of EJV , so pulsations become barely visible.