When the supply curve for loanable funds is highly inelastic (steep), which policy is most effective at boosting both saving and investment?

Explanation

Reducing the budget deficit (Option A) is the most effective policy because when the supply of loanable funds is inelastic, lowering the deficit frees up funds for private saving and investment. Increasing the deficit or offering investment tax credits are less effective under these conditions, and none of the policies would be ineffective as suggested in Option D.