Final answer:
The cost of each pepper plant is B) $3.40. Hence, B) is correct.
Step-by-step explanation:
To find the cost of each pepper plant, we need to set up a system of equations. Let x represent the cost of each pepper plant.
From the first customer's purchase, we can write the equation: 12x + 6y = 66.30, where y represents the cost of each tomato plant.
From the second customer's purchase, we can write the equation: 9x + 12y = 81.60.
We can solve these equations simultaneously to find the values of x and y.
Solving these equations, we find that x is approximately 3.40. Therefore, the cost of each pepper plant is $3.40, which corresponds to option B.