Multiply the numerators and the denominators, then simplify.<br><br>
&bull; \( \frac{12}{7} \times \frac{3}{4} = \frac{12 \times 3}{7 \times 4} = \frac{36}{28} \)<br>
&bull; The HCF of 36 and 28 is 4.<br>
&bull; \( \frac{36}{28} = \frac{36 \div 4}{28 \div 4} = \frac{9}{7} = 1\frac{2}{7} \)<br><br>
Final Answer: C: \( 1\frac{2}{7} \)