Answer: Participation strategy
Explanation: Participation strategy refers to the strategy in which the management tries to make all the individuals in a group to collectively work for the accomplishment of a goal. It refers to associate the workers in an objective to give them a sense of superiority and belongingness towards that goal.
In the given case, Gilbert is trying to make the employees to fell the awareness towards the project by taking their ideas ans suggestions into consideration.
Hence from the above we can conclude that the correct option is E.