**Core Concept**
The concept of "good attachment" in breastfeeding refers to the effective latching and positioning of an infant on the mother's breast, allowing for efficient milk transfer and comfortable feeding. This is crucial for establishing a strong milk supply, preventing nipple soreness, and promoting overall breastfeeding success.

**Why the Correct Answer is Right**
Good attachment is characterized by the infant's mouth covering the areola, with the tongue extended to the edge of the areola, and the lips flanged outward. This positioning allows for the infant to effectively express milk from the breast, and the mother to feel a comfortable, gentle tugging sensation. The correct answer will reflect an indication of poor attachment, which can lead to difficulties in breastfeeding.

**Why Each Wrong Option is Incorrect**
* **Option A:** A correct indication of good attachment, as it describes the infant's mouth covering the areola and tongue extended to the edge of the areola.
* **Option B:** This option may describe a situation where the infant is not properly attached, but it is not the best answer as it does not clearly indicate "does not indicate an infant good attachment".
* **Option C:** This option may also describe a situation where the infant is not properly attached, but the best answer is not provided as per the question.
* **Option D:** This option is the best answer as it describes an infant who is not "tongue tied" and has good mobility of the tongue which is a clear indication of good attachment.

**Clinical Pearl / High-Yield Fact**
Infants with tongue-tie (ankyloglossia) may have difficulty attaching to the breast and may require surgical intervention to release the tongue.

**Correct Answer:** D.