Answer:
A, C
Step-by-step explanation:
David is wrongly attributing the lack of the family eating together as the cause of his sons acting out, he is attributing cause where none have been found. His first approach should be to find out the reason why his sons are acting out.
The second error David is making is that research especially social science study results dwell on majority, an average and at such may not necessarily apply to everyone as individual needs deffer and what worked for a particular group may not necessarily work for another.