Step 1 — Read the full sentence with all parts:
(a) In a conflict, speak in a pleasant way
(b) send appropriate non-verbal messages to the other person
(c) and match your non-verbal behaviour
(d) to the spoken message
Step 2 — Check for grammatical consistency:
- Part (a) uses the imperative form: "speak."
- Part (b) also uses the imperative form: "send."
- Part (c), however, begins with "and match your non-verbal behaviour."
Step 3 — Spot the error:
The phrase in part (c) is incomplete and awkward. It should be "and match your non-verbal behaviour with the spoken message," instead of just "and match your non-verbal behaviour." Without "with," the construction is grammatically flawed.
Step 4 — Correct form:
"In a conflict, speak in a pleasant way, send appropriate non-verbal messages to the other person, and match your non-verbal behaviour with the spoken message."
Step 5 — Conclusion:
Thus, the grammatically incorrect phrase is in part (c).
Final Answer:
The correct option is (C) : c.