Final answer:
The statement that expresses a true proportion is Option C, where the ratios 3:5 and 12:20 both simplify to 3:5, confirming a true proportion.
Step-by-step explanation:
The student's question asks which of the given options expresses a true proportion. A true proportion occurs when two ratios are equal. We need to check each option to see which one demonstrates this equality.
- Option A: The ratios 2:3 to 3:2 are not equal as the cross multiplication would give 4:9.
- Option B: The ratio 14:18 reduces to 7:9, which is not equal to the ratio 2:3 when simplified.
- Option C: The ratio 3:5 is equal to the ratio 12:20, as both simplify to 3:5 when reduced. This is a true proportion.
- Option D: The ratio 42:7 simplifies to 6:1, which is not equal to the ratio 6:2 when simplified.
Therefore, the statement Option C expresses a true proportion.