At a smoothie stand, you can order a fruit smoothie in three different sizes: small, medium, or large. You can choose strawberries, mango, or both fruits. Then, you can choose to add yogurt or not. The tree diagram below shows all possibilities. If all the types of smoothies are equally likely to be ordered, what is the probability that someone will order a smoothie with strawberries and yogurt in it? * A) 1/8

B) 1/3

C) 9/18

D) 1/6