Ricardo is a gifted artist who suffered some minor strokes. When asked to draw his cat, he only draws half a cat, he only draws the left side of his cat. Although there is nothing wrong with his vision, he's only aware that he drew the left side to his cat when you point it out to him. Ricardo's condition is known as - - - -

Homonymous Hemianopia

Explanation:

Homonymous Hemianopia is a medical condition that make a person experience a loss of vision on  on the same side of both eyes. But, they personally unaware of this loss. In their own perspective, their vision is completely normal. This is why Ricardo might not aware that he is only drawing the left side of the cat.

This condition typically occurs when their brain is experiencing some sort of damage within the visual pathways. Typically, the damage can occurs when people are experiencing either stroke, trauma from some sort of collision, after math of brain surgery, or even tumor.

the answer to your question is,

d. when a child was born.

-mabel < 3