Step 1: Understand the ordering task.
We must arrange the steps of forming a teacher's positive attitude, labelled $K, L, M, N, O$, in proper sequence.
Step 2: Start with the foundation (K).
Developing trust in children is the first base on which any relationship is built, so K comes first.
Step 3: Build on trust with experience (L).
Once trust exists, positive experiences accumulate, so L follows.
Step 4: Convert experience into beliefs (M).
Repeated good experiences shape inner values and beliefs, so M comes next.
Step 5: Solidify into enduring attitude (N).
Beliefs harden into stable, lasting attitudes, so N follows.
Step 6: Express outwardly (O).
Finally the attitude shows in observable behaviour, so O is last.
Step 7: Write the sequence.
\[ K \to L \to M \to N \to O \]
This is option C.
\[ \boxed{\text{C. K} \to \text{L} \to \text{M} \to \text{N} \to \text{O}} \]