If Suzy is looking to increase the number of symbiotic microorganisms in her body, the best option from the choices given would be A. Yogurt.
Yogurt contains live cultures of "good" bacteria, such as Lactobacillus and Bifidobacterium, which are probiotics that can help promote a healthy gut microbiome. A healthy gut microbiome has been linked to numerous health benefits, including improved digestion, better immune function, and even mental health benefits.
Kiwi, pizza, and salad do not necessarily contain high amounts of probiotics, although they may have other health benefits. Kiwi is a good source of vitamin C and dietary fiber, pizza is high in calories, fat, and sodium, and salad can be a healthy option if it includes a variety of vegetables and a balanced dressing.