Answer:
C. If Diane gets a new job, it will cost her money.
Explanation:
The law of syllogism follows the pattern
If a = b
and b = c
then a = c
In this question, the syllogism is
(a) If Diane gets a new job = (b) she'll need new clothes.
(b) If she needs new clothes = (c) it will cost her some money.
(a) If Diane gets a new job = (c) it will cost her some money.