Answer: D
Explanation: the answer is d
The answer is the last one because infinitive phrases need a to- with a verb to it like to visit. to was used and visit is a verb because you can visit things like the store, For Example: we went outside to visit the store.
due dilligence is the act and being percise or careful in order to fufuil a legal requirement.
* Im kind of confused becuse of how you worded it but I think youre aking about dilligence now? And not due dilligence? *
You can be more dilligent in class by taking your time and putting more effort into your action/work
Try this pdf.
It's quite easy to understand and to formulate your opinion on the subject.
Hope it helps and good luck!