## Core Concept
The question tests the understanding of methods used for disinfecting spores, which are highly resistant forms of microbial life. Effective spore disinfection requires potent methods due to their high resistance to heat, chemicals, and radiation.

## Why the Correct Answer is Right
The correct answer, , involves the use of **autoclaving** or **steam sterilization** under pressure, which is a widely accepted method for eliminating spores. Autoclaving uses high-pressure steam to achieve temperatures above 100°C, typically at 121°C for 15-20 minutes, which is sufficient to kill spores by denaturing proteins and disrupting cellular components.

## Why Each Wrong Option is Incorrect
- **Option A:** - This option is incorrect because while **pasteurization** does involve heat treatment, it is not sufficient to kill spores. Pasteurization typically involves heating to 72°C for 15 seconds or 63°C for 30 minutes, followed by rapid cooling, which is effective against many bacteria and viruses but not spores.
- **Option B:** - This option is incorrect as **ethylene oxide gas sterilization** is indeed effective against spores but is typically used for heat-sensitive materials. However, the question seems to focus on a method specifically highlighted for spore disinfection, making autoclaving a more directly correct and universally applicable answer.
- **Option D:** - This option is incorrect because **UV light** is not effective against spores due to their high resistance. UV light can disinfect surfaces by damaging DNA but is not reliable for eliminating spores.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **autoclaving** is the gold standard for spore elimination in medical and laboratory settings. It's essential to use the correct temperature, pressure, and exposure time to ensure all spores are killed. This method is critical in preparing surgical instruments and in microbiology labs to prevent infection and contamination.

## Correct Answer Line
**Correct Answer: C. .**