Dimitri Crawled Around, Growling to Himself, Sometimes Approaching Other Children

Dimitri crawled around, growling to himself, sometimes approaching other children. Nichol told him that he should just go home. Dimitri crawled over to the large blocks where he arranged them as a three-sided enclosure with boards for a roof. Then he growled that he was going into his own lion den. What type of a construction project was this?

A) One from natural encounters.
B) One stemming from mutual interests of teachers and children.
C) One stemming from teacher concerns.
D) One stemming from thematic concerns.