Arrange the given combustible substances in decreasing order of calorific value:
(1) hydrogen`" "`(2) charcoal
(3) petrol`" "`(4) LPG
(5) wood

Options

A. 2 3 1 4 5
B. 1 4 3 2 5
C. 2 1 4 5 3
D. 2 1 3 5 4

Explanation

To arrange the given combustible substances in decreasing order of calorific value, we need to understand the calorific values of each substance. The calorific value is the amount of energy released when a substance is burned. Here’s how we can approach the problem step by step:

### Step-by-Step Solution:

1. **Identify the Substances**: The substances we need to arrange are:
- Hydrogen
- Charcoal
- Petrol
...