What Mechanistic Intermediate Is Used to Explain the Preference for Addition

Multiple Choice

What mechanistic intermediate is used to explain the preference for addition of the Br atom, of HBr, to the internal carbon of a terminal alkyne?

A) Formation of an intermediate with partial positive charge on a primary carbon
B) Formation of an intermediate with partial positive charge on a secondary carbon
C) Addition of the H atom to the carbon already with an H.
D) Addition of H, from HBr, to the least hindered carbon.
E) Steric hindrance for the approach of the Br atom to the primary carbon.