Abdominal breathing is not necessary in the Eight Brocades. But, anytime you can incorporate it into your practice, it will make your training more efficient.
The type of breathing in A. does not make sense. if you are drawing in the abdomen, you should be lifting the pelvic floor, as in B. This is reverse abdominal breathing.
Conversely, you can use the more gentle and relaxing normal abdominal breathing, in which you inhale and expand the abdomen and gently push the pelvic floor down.
One or the other.
A note about focusing on your exhalation; emptying the lungs completely is a great way to develop deeper breathing habits. but, be aware of the duration of your breaths as they pertain to the time of year.
In Fall and Winter, energy is waning and we can practice more "Yang" exercises safely. This means, your exhalation should be as long as, or longer than, your inhalation. As you exhale slowly and mindfully, your body's energy field expands outward, making the body more Yang.
In the Spring/Summer, you want to make the body more Yin, so focus on extending the inhalation.