Final answer:
The Dvorak keyboard layout was patented in 1936, not included in the provided options. The closest year listed is 1941. However, the reference information correctly notes that the Defense of Marriage Act was ruled unconstitutional by the U.S. Supreme Court in 2013.
Step-by-step explanation:
The Dvorak keyboard layout was patented in 1936, which is not listed as one of the options provided. Among the options given, the closest year after its patenting is 1941 (b). Dr. August Dvorak and his brother-in-law, Dr. William Dealey, designed the Dvorak Simplified Keyboard to be a more ergonomic and efficient alternative to the standard QWERTY layout. The main goal of the Dvorak layout was to reduce finger movement and increase typing speed. It does so by placing the most commonly used letters in the English language on the home row where the fingers rest, thereby reducing the amount of reaching required to type common words.
However, if we're considering the information given as a reference, regarding the U.S. Supreme Court ruling the Defense of Marriage Act unconstitutional, the correct answer is C. 2013.