Final answer:
In phonics instruction focused on short vowel keywords, words like 'dog', 'cat', and 'box' should be avoided because their pronunciation can obscure the clarity of the short vowel sounds.
Step-by-step explanation:
When teaching phonics and focusing on short vowel keywords, it's essential to use words that clearly demonstrate the short vowel sounds without ambiguity. Words that typically have short vowels are those like hat with a short a, bed with a short e, and pig with a short i. However, words like dog, cat, and box might not be suitable as short vowel keywords. The reason is that the word dog has a short vowel that sometimes sounds close to a short o, but it can vary in pronunciation. The word box includes the letter x, which can obscure the vowel sound with its own 'ks' sound. Therefore, the best answer is B. Dog, cat, and box should be avoided in phonics instruction when teaching short vowel sounds.