For indicating time, the best answer is C- During, because this word tells a reader when an action is taking place.
Again implies that something has been done before, and is being done again, but does not imply <em>when</em> it is being re-done.
Furthermore is a word with a similar meaning to "Also", so it is not connected to the idea of time.
Besides generally means "other than" which, again, has no connection to time.
The participle is "digging." Most participles end in -ing. It modifies "man", describing what the man is doing.
Answer:
ability to write better
Explanation:
it means that they will be able to write better
