Choose the most essential part of a shoe from the following options (that is, the part without which it would not truly be a “shoe”):

Introduction / Context:
This is a verbal reasoning question about essential components. The idea is to identify which part is absolutely necessary for something to be recognised as a shoe, regardless of style or material. Understanding “essential” versus “optional” features is a key skill in such analogy and component questions.

Given Data / Assumptions:

• The object is a “shoe”.

• The options given are: Lace, Sole, Leather and Walking.

• We must decide which option names a part without which an item would not reasonably be considered a shoe at all.

• We assume modern and traditional shoes of different designs: slippers, sandals, sports shoes, formal shoes, etc.

Concept / Approach:
We distinguish between necessary physical components and optional features or uses. A shoe, by definition, is a piece of footwear that covers and protects the foot and allows it to make contact with the ground. The part that makes contact with the ground and supports the foot is the sole. Other components like laces or leather can be present or absent, but a shoe without any kind of sole is not functionally a shoe.

Step-by-Step Solution:
Step 1: Consider “Lace”. Many shoes, such as slippers, sandals and slip-ons, have no laces at all, yet they are still clearly shoes. Therefore, laces are not essential. Step 2: Consider “Leather”. Shoes can be made from many materials: leather, synthetic fabric, rubber, canvas, foam, plastic, and so on. Leather is common but not necessary. Sports shoes and flip-flops are often not leather but are still shoes. Step 3: Consider “Walking”. Walking is an activity performed with shoes, not a physical part of the shoe. It describes a function, not a component. Step 4: Consider “Sole”. Every shoe has some form of sole: the flat or shaped bottom part that protects the foot from the ground. Without a sole, the object cannot function as footwear; it would be more like just a piece of upper fabric or decoration. Hence, the sole is an essential part.

Verification / Alternative check:
Imagine a shoe with no laces but with a sole (like a slipper). It still works as a shoe. Imagine a shoe made entirely of rubber, again with a sole — still a shoe. But imagine only the upper part, with nothing beneath your foot; it would not protect the bottom of the foot and would not function as a shoe. This confirms that the sole is the truly essential component.

Why Other Options Are Wrong:
“Lace” is optional — many shoes use Velcro, elastic, buckles or simply slip-on designs.
“Leather” is just one possible material and not required for something to qualify as a shoe.
“Walking” is an action performed using shoes, not a physical part of the shoe itself.

Common Pitfalls:
Some candidates are misled by thinking of traditional leather lace-up shoes and pick either lace or leather. It is important to think broadly across different shoe types and focus on functional necessity, not on the most familiar style.

Final Answer:
The most essential part of a shoe is the sole.