To answer this question, you need to understand the definitions and characteristics of a walkthrough and an inspection. Let's go through each option to understand why it is correct or incorrect:
Option A) An inspection is led by the author, whilst a walkthrough is led by a trained moderator.
This option is incorrect. In a walkthrough, the author typically guides the session, while in an inspection, a trained moderator or inspector leads the process.
Option B) An inspection has a trained leader, whilst a walkthrough has no leader.
This option is incorrect. Both a walkthrough and an inspection typically have a leader or facilitator who guides the process.
Option C) Authors are not present during inspections, whilst they are during walkthroughs.
This option is incorrect. Authors may or may not be present during both walkthroughs and inspections. The presence of authors can vary depending on the specific context or purpose of the walkthrough or inspection.
Option D) A walkthrough is led by the author, whilst an inspection is led by a trained moderator.
This option is correct. The main difference between a walkthrough and an inspection is that in a walkthrough, the author typically leads the session, while in an inspection, a trained moderator or inspector leads the process.
Therefore, the correct answer is Option D. A walkthrough is led by the author, whilst an inspection is led by a trained moderator.