What is the best way to rewrite the following sentence to make it parallel in structure?

In order to succeed in school, you should pay attention during class, to study for at least 15 minutes every day, and keeping a positive attitude.


A)In order to succeed in school, you should pay attention during class, study for at least 15 minutes every day, and keep a positive attitude.

B)In order to succeed in school, you should pay attention during class, studying for at least 15 minutes every day, and be sure to keep a positive attitude.

C)In order to succeed in school, you should have paid attention during class, study for at least 15 minutes every day, and keep a positive attitude.

D)In order to succeed in school, you should pay attention during class, to study for at least 15 minutes every day, and keeping a positive attitude.

E)In order to succeed in school, you should be paying attention during class, studying for at least 15 minutes every day, and keep a positive attitude.