The first sentence: the tin roof shone in the sun, and the front lawn was green and inviting is the correct answer. When they tell you that they want a precise and clear word choice, they are looking for the sentence that brings the most vivid image into your mind. The sentence that describes the scene the best.
Instead of: the ball, they want: the blue, rubber ball, which was deflated and lay pathetically on the ground.
I hope this helped you.