To FIND the last sentence in the arrangement, we will have to find the first five sentences. 

The first sentence of the arrangement will be the option E as it introduces us to the main term and idea of the paragraph, i.e., Cyberslacking in the office.

The second sentence in the arrangement will be the option C as it further GIVES out the consequence of cyberslacking in the office.

The third sentence will be the option A as it contains the word 'hence', concluding the definition and its immediate consequence in the office.

The fourth sentence will then be the option F as it now introduces us to the fact that some companies use surveillance to monitor what their employees are doing online. $

The fifth option will be the option B as it is in the flow of the previous sentence only, i.e., the result of a high LEVEL of surveillance in the office. $

Hence, the last sentence of the arrangement will be the option D as it is the only one left and also, it is giving a completely NEW and positive point about cyberslacking unlike the previous sentences.$