The italicized word OVER can be used either as a preposition or as an adverb in a sentence. In this particular sentence, the correct answer is adverb.
When over is used as an adverb, it is not followed by any word which would create a phrase along with it (as is the case here). Compare OVER as a preposition (A bird flew over the lake - we can see over what) and OVER as an adverb (Could you come over - we don't know over where or what).
Answer:
Explanation:
My intentions after graduating high school, are going to some engineering college, and becoming and engineer.
The answer to your question is,
Which type of volunteer work is the most time consuming?
-Mabel <3