Research by Renée Baillargeon and her colleagues documents that infants as young as three to four months expect objects to be in the sense that other objects cannot move through them and in the sense that objects continue to exist when they are hidden.
a. subject to gravity; transient
b. consistent; existential
c. substantial; permanent
d. opaque; substantial

The correct option is option "b. Consistent; Existential

Explanation: Renée Baillargeon and her colleagues, studied the sense in children and infant, and how their understand the environment. They discovered that infant as young as three to four months wants a object to be consistence, this explains why infant of three to four months cry most when they can't see their mother, and will always want to be carried by their mother, this is because they have seen their mother as an object which should not be moved from their sight.

They also observed the infant of three to four months cry when their can't see their mother because, they believe their mother is still in existence even though it is hidden from they sight, so they cry to call back her attention to come back to sight.

early settlements on the subcontinent. both the indus and the ganges rivers carried rich silt from the mountains to the plains. when the rivers flooded, the silt spread over the plains and made the soil in the river valleys fertile for farming.

where's the