Which infant most needs a developmental referral for a gross motor delay? 1. The 2-month-old who does not roll over. 2. The 4-month-old who does sit without support. 3. The 6-month-old who does not...

Which infant most needs a developmental referral for a gross motor delay?

1. The 2-month-old who does not roll over.

2. The 4-month-old who does sit without support.

3. The 6-month-old who does not creep.

4. The 9-month-old who does not stand holding on.