Question $1$: We learned that when calling subprograms or functions that we can pass data to the subprogram or function by $$value$$ or by $$reference$.$ Describe what each approach is$,$ how it works and what the potential security disadvantage is when passing parameters by reference.

Question $2$: Recursion is one way of implementing recursion in programs to solve complex problems. Select one of the following three common computer science problems and describe how recursion can be used to solve this problem more efficiently $($sorting$,$ minimum cost spanning tree, knapsack problem$).$ You must generally describe the algorithm that would be used to solve the problem and detail how recursion makes the algorithm more asymptotically efficient.