Choose the idiom that conveys the meaning below:

To express approval or dissatisfaction by choosing to leave an organisation, event, or situation.

The correct option is Vote with one's feet.

Explanation:
An idiom is a phrase or expression whose figurative meaning is different from the literal definition of its individual words. Let's break down the meaning of the given options to find the correct match:

1. Vote with one's feet: This idiom means to indicate one's opinion, dissatisfaction, or disagreement by physically leaving a situation, event, business, or organization, or by choosing not to support or participate in it any longer.
2. Cast the first stone: This means to be the first to accuse, attack, or criticize someone for doing something wrong.
3. Put one's foot in one's mouth: This means to say something embarrassing, foolish, or tactless by mistake.
4. Follow in someone's footsteps: This means to pursue the same career, lifestyle, or course of action as someone who came before you.

Thus, the idiom that directly aligns with expressing disapproval or choice by leaving a situation is Vote with one's feet.