Boy would be better translated as लड़का. बच्चा refers to a male child for which the age is implied to be quite young (an infant or toddler), while लड़का/boy could refer to somebody older (a teenager for example).
It should accept my answer. I have put 'kid' instead of 'the child' ,its the same meaning only
I put "a child is not on the table" - can someone clarify why this was incorrect?