Concept:Algebraic thinking relies on two key ideas: generalization (finding patterns that hold true in many cases) and symbolisation (using symbols like variables to represent those patterns).Explanation:Generalization means looking at specific arithmetic examples and creating a rule that works for all similar cases. For instance, seeing that 3+5=5+3 leads to the general rule a+b=b+a.Symbolisation uses letters or symbols to stand for numbers, making it easier to state and work with these general rules.Option (b) correctly states that algebra involves creating generalizations from arithmetic. Option (c) correctly states that algebra involves representing patterns and regularities in our world.Options (a) and (d) are incorrect because they suggest memorizing symbols or that algebra cannot be taught concretely, which is false.Answer:D. (b) and (c)