Nine-month-old Sharla can retrieve her ball when her mother hides it under a blanket. Sharla has begun to master object permanence and is in the substage of sensorimotor development. tertiary circular reaction

b.
mental representation

c.
coordination of secondary circular reactions

d.
primary circular reactions

Need 5. reflection what factors did you use to determine the validity of your sources? (what was most important and guided your decision to determine validity? ) what factors did you use to determine the reliability of your sources? what was the most important and guided your decision to determine reliability? what form of media resources (internet, publications, music, advertisements, video, etc.) do you think were the most valid and reliable for your question? support your answer. what was your best source? support your answer.