Pick two best ways of standardizing the following:

Johnson finished his last project in only 4 days. Because he's such an efficient worker, he deserves a promotion.

a.

This is not an argument, because it explains why Johnson is an efficient worker.

b.

1. Johnson deserves a promotion.

2. Johnson finished his last project in only 4 days.

3. Therefore, he's such an efficient worker.

c.

1. Johnson's such an efficient worker.

2. Johnson finished his last project in only 4 days.

3. Therefore, he deserves a promotion.

d.

1. Johnson finished his last project in only 4 days.

2. He's such an efficient worker

3. Therefore, he deserves a promotion.