This is a tricky one because it requires you to use formal logical reasoning. Here's a diagram of the argument:
Premise 1: Understand architecture of personal computers - -> computer scientist Premise 2: Appreciate the advances in technology in the last decade - -> understand the architecture of personal computers
These can be combined to form: Appreciate advances - -> understand the architecture - -> computer scientist
The conclusion has this argument background, as it could be diagrammed as:
Computer scientist - -> appreciate the advances
So, we know that the flaw in the argument is that the conclusion has reversed the analysis of the premises. Now, we just need to find an answer choice which matches that.
Answer (B) is correct because it pinpoints the mistake in the conclusion. The argument is assuming that because only computer scientists understand architecture, and only those who understand the architecture appreciate the advances, that ALL computer scientists appreciate these advances. That's not true, as there can be a subset of computer scientists who aren't covered by the argument.