While observing a second-grade student reading a short passage, the teacher notes that the student is having difficulty decoding words containing two syllables in which the first linguistic unit follows the open syllable rule. Which of the following sets of words can the teacher use to provide additional instructional support for the student's specific area of need?

These words do not follow the open syllable rule in their first syllable. For example, "fur" in "further" and "dir" in "dirty" both have closed syllables, which end in consonants and produce short vowel sounds. This set would not effectively support the student's need to practice decoding open syllables.

In this set, the first syllables are also closed. "Hel" in "helmet," "bas" in "basket," and "hap" in "happy" all end with consonants, resulting in short vowel sounds. Although "con" in "confuse" is open, the majority of words do not fit the necessary pattern for the student's specific decoding challenges.

While "lighthouse" has an open first syllable ("light"), the other words such as "aw" in "awful," "sound" in "soundproof," and "clue" in "clueless" do not follow the open syllable rule consistently. Thus, this set does not provide adequate practice for the student's needs.