The sentence that offers the strongest support that ombey valued a close connection with his son is B. Those three words conveyed the one idea of Mr Dombey’s life.
Those three words are "Dombey and son". The passage continues "The earth was made for Dombey and Son to trade in, and the sun and moon were made to give them light. Rivers and seas were formed to float their ships; rainbows gave them promise of fair weather; winds blew for or against their enterprises; stars and planets circled in their orbits to preserve inviolate a system of which they were the centre."
Now he had a son to continue his work as trader. The world belongs to him and his son, makes sense one more time.