S. M. Mohsin proposed a two-step view of attitude change—(i) exposure/attention and (ii) internalization leading to stable change—highlighting the sequential nature of persuasion.
Festinger is associated with {cognitive dissonance}; Heider with {balance} (P–O–X) theory. Therefore (C) is correct.
\[
\boxed{\text{(C) S. M. Mohsin.}}
\]