Gold numbers of protective colloids A, B, C and D are `0.50, 0.01, 0.10` and `0.005` respectively. The correct order of their protective powers is

Options

A. `D lt A lt C lt B`
B. `C lt B lt D lt A`
C. `A lt C lt B lt D`
D. `B lt D lt A lt C`

Explanation

To determine the correct order of protective powers of the protective colloids A, B, C, and D based on their gold numbers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Gold Numbers**:
Gold number is defined as the minimum weight of a protective colloid required to prevent the coagulation of 10 ml of a standard gold sol when 1 ml of a 10% NaCl solution is added. A lower gold number indicates a higher protective power.

2. **List the Gold Numbers**:
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