His attitude . . . . . . . . his work is very negative.

In this sentence, the preposition that appropriately fits in the blank to convey the intended meaning is "in". The complete sentence would be:

"His attitude in his work is very negative."

This usage of "in" indicates that the negativity is associated with his work or is reflected within his work. It's a common preposition to use when describing someone's attitude or behavior in a specific context, in this case, his work.

The other options do not fit as well in the context of the sentence:

Option A: to would imply a different relationship between attitude and work.
Option C: about and Option D: of are less commonly used in this context.

So, the correct answer is Option B: in.