Correct answer is (d) When angles are connected to gusset plates by welding or bolting only through one of the two legs resulting in eccentric loading, there is a uniform stress distribution over cross section.
Easiest explanation: Angles if axially loaded through centroid can be designed as plates. Angles connected to gusset plates by welding or bolting only through one of the two legs results in eccentric loading, causing non-uniform stress distribution over cross section. When load is applied by connecting only one leg of member, there is shear lag at the end connection.