Final answer:
The smallest number among the given options is option C) 2 × 10⁻⁵.
Step-by-step explanation:
The smallest number among the given options is option C) 2 × 10⁻⁵.
When comparing numbers in scientific notation, we look at the powers of 10. A smaller power of 10 indicates a smaller number. In this case, 10⁻⁵ in option C) is the smallest power of 10, so it represents the smallest number.