Let's use conditional probability to solve this problem. We want to find the probability of a customer purchasing a specialty espresso drink and a food item, so we can use the following formula:
P(specialty espresso drink and food) = P(food|specialty espresso drink) * P(specialty espresso drink)
We know that P(specialty espresso drink) = 0.56 and P(food|specialty espresso drink) = 0.35, so we can substitute these values into the formula:
P(specialty espresso drink and food) = 0.35 * 0.56
P(specialty espresso drink and food) = 0.196
Therefore, the probability that a randomly chosen customer will purchase a specialty espresso drink and a food item is 0.196 or approximately 0.20 (rounded to two decimal places).
So, the answer is option C: 0.20.