To answer this question, we need to understand the possible reasons for the poor response faced by the end user of the online car dealer.
Option A) The system administrator is telling a lie - This option is not necessarily true. While it is possible that the system administrator may not be providing accurate information, we cannot conclude this without further evidence.
Option B) There is a delay either at the network or client PC or both - This option is likely to be true. Poor response in an online system can be caused by delays in the network connection between the client PC and the server, or by performance issues on the client PC itself. This could include factors such as slow internet connection, high network traffic, or a slow and outdated PC.
Option C) The problem will get solved upon reboot - This option is unlikely to be true. Rebooting the system may help in some cases, but it is not a guaranteed solution for poor response. There may be underlying issues that cannot be resolved by a simple reboot.
Option D) Network capacity will need to be upgraded - This option is not necessarily true. While network capacity could be a factor in poor response, it cannot be concluded without further investigation. The system administrator has already mentioned that there is no problem with the web or DBMS servers, so the issue may not be related to network capacity.
Based on the given information, option B is the most likely explanation for the poor response. It suggests that there is a delay either at the network or client PC, or both, causing the poor response experienced by the end user.