The correct answer is D. None of the mentioned.
The global option results has value hide when the results option is set to hide. The global option fig.width has value 6 when the fig.width option is set to 6. The global option echo has value TRUE when the echo option is set to TRUE.
The global options are set in the knitr options file, which is located in the ~/.knitr directory. The global options can also be set in the knitr preamble, which is located at the top of the R Markdown document.
The global options are used to control the behavior of the knitr package. For example, the results option can be used to control whether or not the results of the R code are displayed in the output. The fig.width option can be used to control the width of the figures in the output. The echo option can be used to control whether or not the R code is echoed to the console.