The density of a gas at `27^(@)C` and `1 atm` is `d`. Pressure remaining constant, at which of the following temperture will its density become `0.75 d`?

Options

A. `20^(@)C`
B. `30^(@)C`
C. `400 K`
D. `300 K`

Explanation

To solve the problem, we need to find the temperature at which the density of a gas becomes \(0.75d\) while keeping the pressure constant. We can use the relationship between density and temperature derived from the ideal gas law.

### Step-by-Step Solution:

1. **Understand the relationship between density and temperature**:
The density \(d\) of a gas can be expressed using the formula:
\[
d = \frac{PM}{RT}
...