Why did David Infect Holloway?

@Prouty99 David asked Holloway how far would he go and what would he do to get his answers... When Holloway said anything and everything.. well David took that as permission for David to do what ever he wanted to do with Holloway to help Holloway get his answers.

Weyland wants to expose Holloway because he knows that Charlie and Shaw will have sex in the night. Exposing Charlie, will automaticaly expose Shaw, in a second degree, like for any virus or bacteria. After the killing of Charlie by Vickers, David examine Shaw and see that the sexual matrix has been restored. So he wakes up Peter Weyland. But all is to read between the lines in the movie. Lindelorf explained it. And it takes sens, explaining lot of cuts in the plot.

This 1s easy and Id guess others have already explained this too. Davids basically acting on orders from his master "Weyland". Like the scene where Vickers asks him "what did he tell you?", to which David replies "try harder." Also Daivd is very curious himself, Weyland wants Imortality, David is reporting bk to him everything what is going on. Weyland wants to know exactly what the black goo is/does and David uses Holloway as the guinea pig, when he asks him how far he would go, what he would do to get answers.