Step 1: Identifying the Velar Sounds.
Velar sounds are produced by obstructing the airflow at the velum, the soft part of the roof of the mouth. The sounds typically produced in this region include the consonants k, g, and m, which are all velar in nature.
Step 2: Analyzing the Options.
- (1) A, k, g, m: This is the correct answer, as all these sounds are velar sounds.
- (2) A, m, ng, g: This includes "m", which is bilabial and not a velar sound, so it's incorrect.
- (3) B, ph, th, kh: These sounds are not all velar. "ph" and "th" are fricatives, and "kh" is a voiceless velar fricative, but this is not a basic velar set.
- (4) D, k, kh, g: This includes "k" and "g", which are velar, but "kh" is a voiceless fricative, which doesn’t fit the basic velar category.
Step 3: Conclusion.
The correct matching set of velar sounds is A, k, g, m. Therefore, the correct answer is option (1).