Which of the following statements indicates that law of multiple proportion is being followed?

Options

A. a) Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio 1:2
B. b) Carbon forms two oxides namely `CO_(2)` and `CO` where masses of oxygen which combine with fixed mass of carbon are in the simple ratio 2:1
C. c) When magnesium burns in oxygen, the amount of magnesium taken for the reaction is equal to the amount of magnesium in magnesium oxide formed
D. d) At constant temperature and pressure 200mL of hydrogen will combine with 100mL oxygen to produce 200mL of water vapour

Explanation

To determine which statement indicates that the law of multiple proportions is being followed, we need to analyze each option based on the definition of the law.

### Step-by-Step Solution:

1. **Understand the Law of Multiple Proportions**:
- The law states that when two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element can be expressed in a simple whole number ratio.

2. **Analyze Each Option**:
...