Which form of "ed" is pronounced like /t/?

The correct choice is associated with the pronunciation of the "ed" ending in the context of regular verbs. The "ed" ending is pronounced as /t/ when the base verb ends in a voiceless consonant sound, which does not cause vocal cord vibration during pronunciation.

In the case of the word "fluffed," the base verb "fluff" ends with the voiceless consonant /f/. Since "fluff" ends in this voiceless sound, the "ed" is pronounced as /t/, resulting in "fluffed" sounding like /flʌft/. This follows the phonological rule governing the pronunciation of past tense forms based on the preceding sound.

Other options demonstrate different contexts where "ed" is pronounced as /d/ or /ɪd/, which occurs when the base verbs end in voiced consonants or specific sounds. Recognizing these phonetic rules is essential in understanding how regular verbs are articulated in their past forms.