Which word provides the best coarticulatory conditions for the target sound /s/?

The word "sea" provides the best coarticulatory conditions for the target sound /s/ because it is positioned at the beginning of the word and is followed by a front vowel sound (/i/). This combination allows for optimal airflow and tongue placement, facilitating clear and crisp articulation of the /s/ sound. When /s/ precedes a front vowel, it tends to resonate well and is produced with clearer acoustic properties, making it easier to hear and perceive.

In contrast, other options present different articulatory contexts that are less ideal for the /s/ sound. For instance, "spoon" starts with /s/ but is followed by a consonant /p/, which can disrupt the airflow needed for a clean /s/ production. "Sob" also starts with /s/, but it is followed by the vowel /ɒ/, which is a back vowel, not as favorable for enhancing the clarity of the initial /s/. Meanwhile, "soup" ends with the same consonant that precedes /u/, which can create a blending effect that softens the clarity of the /s/ sound. Thus, "sea" stands out as the best option for clear coarticulation of the /s/ sound