Parents to invest a lot in their child's financially can't expect to earn back there investment later in life when their children are able to comfortably support them in old age

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.

It is less likely that the shoe will slip while someone is walking

You answer would be c.