Here is a goal: How to Train Your Puppy with Simple Commands

How would you accomplish this goal?

Available choices:
[a]. The key to training is to make each session fun and short. A minute or two for each month of age up to 6 months is a good ballpark figure.
[b]. The key to training is to make each session fun and long. An hour or two for each month of age up to 6 months is a good ballpark figure.
[a].