D. object permanence. A theory by Swiss psychologist Jian Piaget studied and theorized that at certain age of infancy, an awareness is developed that objects and people continue to exist even if they cannot see them. This manifested development is seen when infants play the games of peekaboo or hiding toys under the blankets.
Explanation:
Let Izzy's age be x and Ben's age be y
y=4x
4x-y=0. -----(1)
y= 6+x
x-y=-6 -------(2)
By using elimination
3x=6
x=2
2 years
<span>Native Americans in Ohio, who were not parties, refused to acknowledge treaties signed after the Revolutionary War that ceded lands north of the Ohio River inhabited by them to the United States. In a conflict sometimes known as the Northwest Indian War, Blue Jacket of the Shawnees and Little Turtl of the Miamis formed a confederation to stop white expropriation of the territory. After the Indian confederation had killed more than 800 soldiers in two battles the worst defeats ever suffered by the U.S. at the hands of the Indians President Washington assigned General Anthony Wayne command of a new army, which eventually defeated the confederation and thus allowed European-Americans to continue settling the territory. </span>
