Choose the correct option in italics to complete the sentences.

1. This is mainly caused / down / up to hard work.

2. The team really had / made / took a great effort in the last few months.

3. We’ve worked hard / hardly / strong to establish good distribution channels.

4. This was mainly because / cause / due to a lack of time.

5. I think we underestimated / undermanaged / understated some of the challenges.

6. We had a lot of motivation issues / subjects / topics with our sales force.