What do you mean by external documentation?This type of question contains radio buttons and checkboxes for selection of options. Use Tab for navigation and Enter or space to select the option.optionADocumentation done using code comments, function documentation, module documentation, and so onoptionBAdditional documentation captured in separate filesoptionCFormal documents created using pictures and text that are usually targeted toward users of a systemoptionDComments that are descriptive and explain the code