To solve this question, the user needs to know about the history of toilets and their different types.
Option A: Handicapped toilets are designed for people with disabilities and are equipped with features such as handrails, lower sinks, and wider stalls. This option is incorrect because Arthur Giblin did not invent the first handicapped toilet.
Option B: Modern toilets are the standard type of toilets found in homes and buildings today. This option is incorrect because Arthur Giblin did not invent the first modern toilet.
Option C: Public toilets are toilets that are available for use by the general public. This option is incorrect because Arthur Giblin did not invent the first public toilet.
Option D: Flushable toilets are designed to be flushed with water to remove waste. This option is correct because Arthur Giblin is credited with inventing the first flushable toilet in 1890.