c) He has a harder time seeing 42-degree lines than 45-degree lines, but he can see 35-degree lines best of all
Explanation: When Jake stares at lines oriented at 45 degrees for 5 minutes, he may experience adaptation to those lines, making it harder for him to see lines at a similar orientation, like the 42-degree lines. However, due to the adaptation effect, his sensitivity may improve for lines at a different orientation, such as the 35-degree lines.