A brief information about three substances is given here
X: Transparent, smooth to touch and insulator. Y: Yellow in colour, good conductor of heat and electricity, lustrous. Z: Man-made material, an insulator, used to make switches and handles of cooking utensils. X, Y and Z could be respectively

Options

A. Water, copper, aluminium
B. Glass, gold, plastic
C. Paper, aluminium, copper
D. Silver, gold, copper.

Explanation

To solve the question regarding the identification of substances X, Y, and Z based on their properties, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Substance X:**
- The properties of X are: transparent, smooth to touch, and an insulator.
- Possible candidates for X include glass and water. However, since we need a solid insulator, glass is the best fit.
- **Conclusion:** X is **Glass**.

2. **Identify Substance Y:**
- The properties of Y are: yellow in color, good conductor of heat and electricity, and lustrous.
- The metals that are yellow and fit these criteria include gold and copper. Since gold is well-known for being yellow, lustrous, and an excellent conductor, it is the most suitable choice.
- **Conclusion:** Y is **Gold**.

3. **Identify Substance Z:**
- The properties of Z are: man-made material, an insulator, and used to make switches and handles of cooking utensils.
- The most common man-made insulator used for such purposes is plastic. It is widely used for making handles and switches due to its insulating properties.
- **Conclusion:** Z is **Plastic**.

### Final Summary:
- X = Glass
- Y = Gold
- Z = Plastic