The mother of a 2-month-old baby tells the nurse, "I'm worried because my baby isn't able to sit independently." Which response by the nurse would be appropriate?

"It's a bit too soon. Most babies sit steadily at 4 months"

"Once the first tooth comes in, sitting independently will soon follow"

"That's not unusual because most babies do not sit by themselves until about 8 months"

"That's interesting because most babies sit steadily at 3 months"