The ability to perceive a rod as being continuous behind an occluding block?

The ability to perceive a rod as being continuous behind an occluding block
A.is innateB.is common in one-week old infantsC.can be accomplished by two-month-oldsD.occurs only after sharp acuity is developed
Acuity develops to almost 20/20 vision by the time the infant is
A.one month oldB.two months oldC.six months oldD.more than one year old